1. Patten's Human Embryology: Elements of Clinical Development;Corliss,1976
2. Do we understand development?;Wolpert;Science,1994
3. Basic Histology;Junqueira,1992
4. Migration of the germ cells of human embryos from the yolk sac to the primitive gonadal folds;Witschi;Contrib Embryol Carnegie Inst,1948
5. Observations on the movements of living primordial germ cells in the mouse;Blandau;Fertil Steril,1963