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Exchanging ISO thesauri data using RDF, SKOS and SKOS-XL

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Presentation on theme: "Exchanging ISO thesauri data using RDF, SKOS and SKOS-XL"— Presentation transcript:

1 Exchanging ISO 25964-1 thesauri data using RDF, SKOS and SKOS-XL
Reported by Johan De Smedt TPDL – workshop

2 Presentation Overview
Objective and rationale of the mapping Thesaurus of Concepts Concept relationships custom concept attributes Terms and Term relations custom term attributes Array Group Notes on concepts and on terms hyperlinks in notes Thesaurus and data-set version history

3 Objective (1/2) Make correction and/or update to the Appendix “Correspondences between ISO-2788/5964 and SKOS constructs” of the SKOS Simple Knowledge Organization System Primer The update is needed because ISO :2011 has been published, replacing the earlier ISO standards ISO 2788:1986 and ISO 5964:1985 Provide a reference framework facilitating integration and data exchange of ISO thesaurus data using RDF as a representation language Approach Minimal extensions are made, using SKOS, SKOS-XL and Dublin Core where possible Contributors ISO TC46 WG 8 working on the ISO standard about Thesauri Stella Dextre Clarke, Jutta Lindenthal, Marcia Lei Zeng, Johan De Smedt, Douglas S. Tudhope, Leonard Will Antoine Isaac: Co-Editor of the SKOS Recommendations and MADS/SKOS mapping

4 Objective (2/2) Methodology and Levels of representation compliance
Always align with the specified SKOS semantics SKOS semantics are a top level agreement for sharing KOS information Not requiring label relations Limited concept relationships Always align with the SKOS-XL semantics SKOS-XL semantics are a top level agreement for sharing KOS information Simple label relations Keep with the iso proposed extensions patterns Compound and simple label relationships, thesaurus evolution, arrays, groups, notes and facets Rationale Provide general representation paradigms To date, varying implementations are found for label relations, concept relationships, arrays and groups. Example illustrations of varying mappings for same abstractions are presented in the slide stack Jutta Lindenthal's presentation illustrates ways of dealing with features that are sometimes found in thesauri although not recommended in ISO Allow for maximal tooling, support and exchange Application specific extensions limit the use of the exchanged information to users knowing the application (profile)

5 ISO-25964 mapping reference
See and for an introduction.

6 Thesaurus Skip in WS ISO-25964 SKOS/SKOS-XL/extension Remark Thesaurus
skos:ConceptScheme isPartOf (Thesaurus) skos:inScheme - hasTopConcept (TopLevelRelationship) Not explicitly mapped. The relationship may be derived (see remark) restriction to the sub-properties of skos:broaderTransitive having as range the domain of skos:topConceptOf Example As an example one could refer to the „facets“ of the AAT

7 Top Concepts Skip in WS

8 ThesaurusConcept (1/2) Skip in WS ISO-25964 SKOS/SKOS-XL/extension
Remark ThesaurusConcept skos:Concept - status iso-thes:status Proposed extension - isPartOf (Thesaurus) skos:inScheme - notation skos:notation The datatype of the notation range is set to distinguish different types of notations ThesaurusConcept[ topConcept=true] Has special attribute mapping (see next 2 rows) skos:topConceptOf - isTopConceptOf (TopLevelRelationship) Not explicitly mapped. The relationship may be derived (see remark) sub-properties of skos:narrowerTransitive having the same domain as skos:topConceptOf

9 ThesaurusConcept (2/2) Skip in WS ISO-25964 SKOS/SKOS-XL/extension
Remark HierarchicalRelationship [role] skos:broader skos:narrower sub-properties may be needed to model different hierarchical relationships identified by the attribute "role" (e.g. BTP/NTP, BTI/NTI, BTG/NTG) AssociativeRelationship skos:related sub-properties may be needed to model different associative relationships identified by the attribute "role" CustomConceptAttribute [customAttributeType] custom RDF property The property name depends on the customAttributeType

10 ThesaurusTerm (1/8) Skip in WS ISO-25964 SKOS/SKOS-XL/extension Remark
- rdf:PlainLiteral - xl:Label - preferred simple mapping - extended mapping to handle label relationships PreferredTerm iso-thes:PreferredTerm The restriction of xl:Label to the range of xl:prefLabel is only required for expressing label relations (see ConpoundEquivalence) (ThesaurusConcept) hasPreferredLabel (PreferredTerm) - skos:prefLabel - xl:prefLabel CustomTermAttribute [customAttributeType] requires xl:Label mapping custom RDF property The property name depends on the customAttributeType

11 ThesaurusTerm (2/8 - equivalence example)
skos:Concept AAT: iso-thes:PreferredTerm chordophones skosxl:preflabel skosxl:altLabel iso-thes:SimpleNonPreferredTerm chordophonic instruments iso-thes:SimpleNonPreferredTerm instruments, chordophonic skosxl:altLabel iso-thes:SimpleNonPreferredTerm instruments, string skosxl:altLabel iso-thes:SimpleNonPreferredTerm string instruments skosxl:altLabel (Art & Architecture Thesaurus)

12 ThesaurusTerm (3/8) Skip in WS ISO-25964 SKOS/SKOS-XL/extension Remark
SimpleNonPreferredTerm iso‑thes: SimpleNonPreferredTerm A sub-class of xl:Label and of the union of: the range of xl:altLabel the range of xl:hiddenLabel ThesaurusConcept - hasNonPreferredLabel (SimpleNonPreferredTerm [hidden=false]) - skos:altLabel - xl:altLabel The inverse mapping requires the distinction - SimpleNonPreferredTerm - SplitNonPreferredTerm (see CompoundEquivalence) ThesaurusConcept - hasNonPreferredLabel (SimpleNonPreferredTerm [hidden=true]) - skos:hiddenLabel - xl:hiddenLabel

13 ThesaurusTerm (4/8) complex example EuroVoc
ISSUE 1: equivalence as inferred relation Legend: iso 25964, skos or skos-xl classes, skos and skos-xl properties iso-thes extension to skos or skos-xl Application extension (specialization) - Eurovoc specific - Elaborate alternative (more skos semantics) ThesaurusTerm (4/8) complex example EuroVoc ISSUE 2: semantics of sub-properties of xl:labelRelation iso-thes:PreferredTerm ThesaurusConcept Equivalence iso-thes:SimpleNonPreferredTerm iso-thes:SimpleNonPreferredTerm (hidden=‘true’)

14 ThesaurusTerm (5/8) Skip in WS ISO-25964 SKOS/SKOS-XL/extension Remark
Equivalence implicit in SKOS All skos:altLabel and skos:hiddenLabel having the same language and belonging to the same skos:Concept are equivalent to the skos:prefLabel with the same language of the skos:Concept. - USE the skos:prefLabel has role: USE - UF the skos:altLabel and skos:hiddenLabel have role: UF example iso-thes:PreferredTerm iso-thes:NonPreferredTerm iso-thes:NonPreferredTerm Or alternatively iso-thes:PreferredTerm

15 ThesaurusTerm (6/8 -compound equivalence example)
iso-thes:SplitNonPreferredTerm adopted children skos:Concept children xl:prefLabel iso-thes:plusUseTerm iso-thes:PreferredTerm children skos:Concept adoption xl:prefLabel iso-thes:PreferredTerm adoption iso-thes:plusUseTerm Example: Thesaurus for the Social Sciences (Thesaurus Sozialwissenschaften)

16 ThesaurusTerm (7/8-compound equivalence example)
“adopted children” ↠ “children” [1], “adoption” [2] Legend: mapped ISO aspect skos and skos-xl specification iso-thes extension to skos/skos-xl - compound equivalence (new) - compound equivalence (specialization) change child -> children

17 ThesaurusTerm (8/8) Skip in WS ISO-25964 SKOS/SKOS-XL/extension Remark
SplitNonPreferredTerm iso‑thes: SplitNonPreferredTerm The restriction of xl:Label to a subset of the union of: the range of xl:altLabel the range of xl:hiddenLabel CompoundEquivalence iso‑thes:CompoundEquivalence - iso-thes:plusUF - iso-thes:plusUse (2+) One instance per equivalence; - the split compound term; - two or more preferred terms - USE+ iso‑thes:plusUseTerm A sub-property of xl:labelRelation - UF+ iso‑thes:plusUFTerm example See above Thesaurus for the Social Sciences (Thesaurus Sozialwissenschaften)

18 ThesaurusArray (1/4 – not ordered)
ThesaurusConcept cups hasSubordinateArray ThesaurusArray <cups by form> hasMemberConcept ThesaurusConcept tumblers HierarchicalRelationship (role=NT) ThesaurusConcept stemware HierarchicalRelationship (role=NT) ThesaurusArray <cups by function> hasSubordinateArray hasMemberConcept HierarchicalRelationship (role=NT) ThesaurusConcept coffee cups HierarchicalRelationship (role=NT) ThesaurusConcept icecream cups images from wikipedia

19 iso-thes:subordinateArray iso-thes:subordinateArray
ThesaurusArray (1/4 – not ordered) skos:Concept cups iso-thes:subordinateArray iso-thes:ThesaurusArray <cups by form> skos:member skos:Concept tumblers skos:narrower skos:Concept stemware skos:narrower iso-thes:subordinateArray iso-thes:ThesaurusArray <cups by function> skos:member skos:narrower skos:Concept coffee cups skos:Concept icecream cups skos:narrower

20 ThesaurusArray (2/4 – ordered)
iso-thes:ThesaurusArray <education by age group or grade level> skos:memberList skos:Concept early childhood education rdf:List rdf:first rdf:rest skos:Concept elementary education rdf:List rdf:first rdf:rest skos:Concept secondary education rdf:List rdf:first rdf:rest rdf:first skos:Concept postsecondary education rdf:List New slide ; I kept the screenshot for your information only rdf:rest rdf:first skos:Concept adult education rdf:List rdf:rest rdf:nil (Art & Architecture Thesaurus)

21 ThesaurusArray 3/4 – facet vs narrower
From ISO Figure 4 — Partially expanded classified display of an "industries" class, with node labels indicating changes of facet, for example (people and products) and characteristics of division of arrays, for example (milk by form)

22 ThesaurusArray 4/4 – facet vs narrower

23 ThesaurusArray (5/5) Skip in WS ISO-25964 SKOS/SKOS-XL/extension
The new class is required to distinguish between ThesaurusArray (having sibling concepts) and ThesaurusGroup (grouped concepts need not be sibling concepts) ISO-25964 SKOS/SKOS-XL/extension Remark ThesaurusArray[ordered=false] iso-thes:ThesaurusArray and skos:Collection ThesaurusArray[ordered=true] and skos:OrderedCollection - hasMemberConcept - hasMemberArray skos:member Not ordered array (skos:Collection) - hasMemberConcept<order> - hasMemberArray<order> skos:memberList (rdf:List, rdf:first, rdf:rest, rdf:nil) Ordered array (skos:OrderedCollection) - isPartOf skos:inScheme - notation skos:notation - hasSubordinateArray iso-thes:subordinateArray Domain = skos:Concept Range = skos:Collection - hasSuperOrdinateConcept iso-thes:superOrdinate Inverse of iso-thes:subordinateArray

24 ConceptGroup (1/3) (Deutsche Nationalbibliothek)
ConceptScheme „Gemeinsame Normdatei (GND)“ skos:Concept Label inScheme:gnd SWD-Sachgruppen node-label inScheme:vocab/gnd-sc iso-thes:ConceptGroup Philosophie skos:notation 4 skos:notation 4.1 iso-thes:ConceptGroup Philosophie (Allgemeines) iso-thes:subGroup skos:member skos:notation 4.5 skos:Concept Philosophie iso-thes:ConceptGroup Ethik, Philosophische Anthropologie, Sozialphilosophie iso-thes:subGroup skos:narrower skos:member iso-thes:ConceptGroup Politik, Militär The iso-thes:ConceptGroups in this example are part of the „GND-Systematik“ formerly „SWD-Sachgruppen“ It is a skos:ConceptScheme (vocab/gnd-sc) different from the ConceptScheme „Gemeinsame Normdatei (GND)“. The ConceptGroups („Sachgruppen“ = „gnd:SubjectCategory“ in the RDF representation form a hierarchically organised two-level systematics used to group concepts of the GND. One concept can be member of 1..n ConceptGroups (example here: „Politische Philosophie“). ConceptGroups of the GND-Systematik are not used for cataloguing documents. Explanation kindly provided by Esther Scheven via mail 14. September 2012: „Anschließend vergeben wir Schlagwörter (nur Reihe A = Bücher innerhalb des Buchhandels) und die DDC-Notation (für alle Reihen) als klassifikatorischen Zugang. Früher haben wir das Dokument mit den SWD-Notationen ("SWD-Sachgruppen") zusätzlich zu den Schlagwörtern erschlossen, um einen systematischen Zugang anbieten zu können. Das wurde schon vor vielen Jahren aufgegeben und heute bekommen die Dokumente nur noch die Schlagwörter. Indirekt kann man über die Schlagwörter auch die Dokumente nach der SWD-Systematik (heute GND-Systematik; früher offiziell "SWD-Sachgruppen" genannt) suchen.“ skos:notation 8 skos:notation 8.1 skos:Concept Politische Philosophie iso-thes:ConceptGroup Politik (Allgemeines), Politische Theorie skos:member iso-thes:subGroup

25 ConceptGroup (2/3) Skip in WS
<?xml version="1.0" encoding="UTF-8"?> <rdf:RDF xmlns:owl="http://www.w3.org/2002/07/owl#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#" xmlns:gnd="http://d-nb.info/gnd#"> <gnd:SubjectHeadingSensoStricto rdf:about="http://d-nb.info/gnd/ "> <gnd:variantNameForTheSubjectHeading>Staatsauffassung <Politische Philosophie></gnd:variantNameForTheSubjectHeading> <gnd:broderTermGeneral rdf:resource="http://d-nb.info/gnd/ "/> <gnd:relatedTerm rdf:resource="http://d-nb.info/gnd/ "/> <gnd:variantNameForTheSubjectHeading>Staatsgedanke <Politische Philosophie></gnd:variantNameForTheSubjectHeading> <gnd:variantNameForTheSubjectHeading>Staatsphilosophie</gnd:variantNameForTheSubjectHeading> <gnd:relatedTerm rdf:resource="http://d-nb.info/gnd/ "/> <gnd:relatedDdcWithDegreeOfDeterminacy3 rdf:resource="http://d-nb.info/ddc/class/ "/> <gnd:preferredNameForTheSubjectHeading>Politische Philosophie</gnd:preferredNameForTheSubjectHeading> <gnd:gndSubjectCategory rdf:resource="http://d-nb.info/vocab/gnd-sc#4.5"/> <gnd:relatedTerm rdf:resource="http://d-nb.info/gnd/ "/> <gnd:gndIdentifier> </gnd:gndIdentifier> <gnd:relatedDdcWithDegreeOfDeterminacy3 rdf:resource="http://d-nb.info/ddc/class/320.01"/> <gnd:gndSubjectCategory rdf:resource="http://d-nb.info/vocab/gnd-sc#8.1"/> <gnd:relatedTerm rdf:resource="http://d-nb.info/gnd/ "/> <gnd:oldAuthorityNumber>(DE-588c) </gnd:oldAuthorityNumber> </gnd:SubjectHeadingSensoStricto> </rdf:RDF>

26 ConceptGroup (3/3) ISO-25964 SKOS/SKOS-XL/extension Remark
ThesaurusGroup iso-thes:ConceptGroup a subclass of skos:Collection - hasSupergroup iso‑thes:superGroup domain = range = iso-thes:ConceptGroup - hasSubGroup iso‑thes:subGroup inverse of iso‑thes:superGroup - hasAsMember skos:member - isPartOf skos:inScheme - notation skos:notation e.g. conceptGroupType micro‑thesaurus iso‑thes:microThesaurusOf a sub-property of skos:inScheme domain = iso-thes:ConceptGroup range = skos:ConceptScheme Example taken from STW Thesaurus for Economics See also case study: and Neubert (2009): Bringing the „Thesaurus for Economics“ on to the Web of Linked Data Example in RDF/XML: and RDF/Turtle: iso-thes:ConceptGroup Securities Markets (or, if subtyped: iso-thes:ConceptGroupSubjectCategory 71107) - iso-thes:subGroup - iso-thes:subGroup - iso-thes:groupMember (is iso-thes:groupMember the agreed property to link concepts to groups, or is it still a proposal in the correspondence table) - skos:inScheme: <../stw> - skos:notation V

27 Notes (1/2) Skip in WS ISO-25964 SKOS/SKOS-XL/extension Remark Note
Example 1 Neubert (2009) Example 2 EuroVoc Work ongoing in the RDF group Notes (1/2) Skip in WS ISO-25964 SKOS/SKOS-XL/extension Remark Note range of skos:note - refersTo tagged embedded hyperlinks work is on going to in the RDF group to type the content explicitly as HTML or XML In RDF1.1: hasScopeNote skos:scopeNote ISO is more restrictive than SKOS hasHistoryNote skos:historyNote hasEditorialNote skos:editorialNote skos:changeNote hasDefinition skos:definition hasCustomNote[ noteType] custom sub property of skos:note or skos:example depending noteType a custom property may be defined Notes with hyperlinks refersTo Neubert (2009) gives an example for structured notes (chapter 3.1.2) in: Bringing the „Thesaurus for Economics“ on to the Web of Linked Data An extension to skos:Note is introduced (zbwext:useInsteadNote) to refer to a hyperlinked concept, related by rdfs:seeAlso: <restrictive business practices> zbwext:useInsteadNote [ rdf:value "For restrictions on market rdfs:seeAlso <market entry> ] . Unfortunately the descriptor „restrictive business practices” is not traceable in the online version of STW. However, use cases may imply semantically associated concepts in definitions, or references to alternative descriptors in scope notes (scope note in the narrower sense), giving advice for indexing and search. (Example from AAT: where the terms in quotation marks could be linked to the respective items.

28 Notes (2/2 – eurovoc example)
Notes with hyperlinks refersTo Neubert (2009) gives an example for structured notes (chapter 3.1.2) in: Bringing the „Thesaurus for Economics“ on to the Web of Linked Data An extension to skos:Note is introduced (zbwext:useInsteadNote) to refer to a hyperlinked concept, related by rdfs:seeAlso: <restrictive business practices> zbwext:useInsteadNote [ rdf:value "For restrictions on market rdfs:seeAlso <market entry> ] . Unfortunately the descriptor „restrictive business practices” is not traceable in the online version of STW. However, use cases may imply semantically associated concepts in definitions, or references to alternative descriptors in scope notes (scope note in the narrower sense), giving advice for indexing and search. (Example from AAT: where the terms in quotation marks could be linked to the respective items.

29 Thesaurus versions and versioned data sets (proposal)

30 VersionHistory (2/2) Skip in WS ISO-25964 SKOS/SKOS-XL/extension
Remark VersionHistory iso-thes:VersionHistorySet The typical unique instance is a set aggregating all “historic versions or variants” of a thesaurus. iso-thes:VersionHistory Each instance details a “historic version or variant” of the thesaurus iso-thes:currentVersion Current “historic version or variant” of a thesaurus iso-thes:isVersionOf Identifies the thesaurus data set of a “historic version or variant” iso-thes:hasVersion Identifies the “historic version or variant” instance providing the historic or variant identifiers of a thesaurus publication (data set) Example taken from STW Thesaurus for Economics See also case study: and Neubert (2009): Bringing the „Thesaurus for Economics“ on to the Web of Linked Data Example in RDF/XML: and RDF/Turtle: iso-thes:ConceptGroup Securities Markets (or, if subtyped: iso-thes:ConceptGroupSubjectCategory 71107) - iso-thes:subGroup - iso-thes:subGroup - iso-thes:groupMember (is iso-thes:groupMember the agreed property to link concepts to groups, or is it still a proposal in the correspondence table) - skos:inScheme: <../stw> - skos:notation V

31 Want a copy of ISO ? Download it from ISO at Order it from your national standards body (e.g. BSI, DIN, ANSI, AFNOR) Some public/academic reference libraries may stock it The XML schema (http://www.niso.org/schemas/iso25964/schema-intro/) and the SKOS/SKOS‑XL mapping (http://www.niso.org/schemas/iso25964/#schema) for exchange of thesaurus data is in an Annex which is available online without charge or password control. Go to

32 References DD8723-5, Data Model for BS In: Structured vocabularies for information retrieval. Part 5. Exchange formats and protocols for interoperability. London: British Standards Institution. Available at: ISO :2011, Thesauri and interoperability with other vocabularies. Part 1: Thesauri for information retrieval. Geneva: International Organization for Standards, August 8, 2011.  ISO Schema and Data Model. W3C Recommendation, SKOS Simple Knowledge Organization System Reference. W3C Recommendation, August 18, Alistair Miles and Sean Bechhofer, eds. Available at: W3C Recommendation. SKOS eXtension for Labels (SKOS-XL). In: SKOS Simple Knowledge Organization System Reference, Appendix B. W3C, August 18, Available at: Correspondences between ISO-2788/5964 and SKOS constructs. In: SKOS Simple Knowledge Organization System Primer. W3C Working Group Note 18 August Antoine Isaac, A. and Ed Summers, eds. Available at: Thesaurus UML Model introduction by Leonard Will: and for an introduction. The “GND-Systematik” - Deutsche Nationalbibliothek (Leipzig, Frankfurt am Main), (ISBN ), available at Detailed documentation about the “Correspondence between ISO 25964, SKOS/SKOS-XL and MADS Models”: This slide pack: Conference proceeding

33 back-up - hidden

34 Equivalence (1/8) simple example (Deutsche National Bibliothek)
skos:Concept gnd: iso-thes: PreferredTerm children skosxl:preflabel iso-thes: SimpleNonPreferredTerm childhood skosxl:altLabel Example: iso-thes: SimpleNonPreferredTerm child skosxl:altLabel

35 Thesaurus Concept (2/3) HierarchicalRelationship + Role
Thesaurus Concept (2/3) HierarchicalRelationship + Role (Deutsche National Bibliothek) skos:Concept Safwa-Sprache skos:Concept Sprache part of Afrikanische Sprachen part-of Benue-Kongo-Sprachen part of Niger-Kongo-Sprachen part of Nigerkordofanische Sprachen skos:broader can have sub-property gnd:broaderTermInstantial skos:broader can have sub-property gnd:broaderTermPartitive skos:Concept Bantusprachen skos:Concept Bantoid skos:Concept Außereuropäische Sprachen skos:broaderTransitive skos:broader can have sub-property gnd:broaderTermPartitive skos:broader can have sub-property gnd:broaderTermPartitive ISSUE: skos:broaderTransitive does not capture different semantics of (e.g.) BTP and BTI

36 ThesaurusArray (1/4) Example from AAT
Please see the accompanying document „example.docx“

37 ThesaurusArray (1/4) (Arts and Architecture Thesaurus)
AAT: skos:Concept mirrors iso-thes: ThesaurusArray <mirrors by form> iso-thes:subordinateArray iso-thes: ThesaurusArray <curved mirrors> skos:member skos:member skos:narrower skos:Concept burning mirrors skos:member skos:Concept flat mirrors skos:narrower In this example it may be questionable from a linguistic/semantic point of view why „curved mirrors“ is a node label rather than a concept. However, this represents a common usage of node labels (or guide terms in the AAT), designating broader concepts not used for indexing. Their function is to bundle sibling concepts.

38 Ordered ThesaurusArray (2/4)

39 ThesaurusArray <ordered> (2/4) (Arts and Architecture Thesaurus)
iso-thes:ThesaurusArray <three-age system> skos:memberList rdf:first skos:Concept Stone Age rdf:List rdf:rest rdf:first iso-thes:ThesaurusArray <transitional periods Stone Age to Bronze Age> rdf:List skos:memberList skos:narrower skos:Concept Chalcolithic rdf:rest rdf:List rdf:first skos:Concept Bronze Age rdf:List rdf:first rdf:rest skos:narrower skos:Concept Eneolithic rdf:rest rdf:List rdf:first skos:Concept Iron Age rdf:List rdf:first rdf:rest skos:narrower skos:Concept final Neolithic rdf:rest rdf:List rdf:first rdf:nil rdf:rest rdf:nil Example from AAT ( ) for an ordered array

40 Ordered ThesaurusArray (3/4)

41 ThesaurusArray <ordered> (3/4) (Arts and Architecture Thesaurus)
iso-thes:ThesaurusArray <Sub-Saharan African Earlier Stone Age periods> skos:memberList Example from AAT ( ) for an ordered array skos:Concept Pre-Chellean rdf:List rdf:first rdf:rest skos:Concept Chelles-Acheul rdf:List rdf:first rdf:rest rdf:nil Additional AAT example in back-up slides

42 Mixed ThesaurusArray (4/4)


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