1. Monozygotic twins in infertile patients with advanced maternal age: case reports and review of the literature 
Navid Esfandiari, D.V.M., Ph.D., H.C.L.D., Monica Kapoor, M.D., Hasan Burjaq, B.Sc., M.T., Paul Chang, M.D., Lynda Gotlieb, R.N., Robert F. Casper, M.D. 
Fertility and Sterility 
Volume 92, Issue 3, Pages 1168.e e12 (September 2009)
DOI: /j.fertnstert
Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
Ultrasound image of monochorionic, monoamniotic intrauterine twin pregnancy with two fetal heartbeats (case 1).
Fertility and Sterility  , 1168.e e12DOI: ( /j.fertnstert )
Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions