1. Cryptorchidism concordance in monozygotic and dizygotic twin brothers, full brothers, and half-brothers 
Morten Søndergaard Jensen, M.D., Gunnar Toft, Ph.D., Ane Marie Thulstrup, Ph.D., Tine Brink Henriksen, Ph.D., Jørn Olsen, Ph.D., Kaare Christensen, D.M.Sc., Jens Peter Bonde, D.M.Sc. 
Fertility and Sterility 
Volume 93, Issue 1, Pages (January 2010)
DOI: /j.fertnstert
Copyright © 2010 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
Establishing six groups of boy pairs in a study population of 1,024,500 Danish boys born
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2010 American Society for Reproductive Medicine Terms and Conditions