1. Witschi E. Migration of the germ cells of human embryos from the yolk sac to the primitive gonadal folds. Contrib Embryol 1948;209:67–80.
2. Lindsley DL, Tokuyasu KT. Spermatogenesis. In: Ashburner M, Wright TRF, editors. The genetics and biology of drosophila, Vol. 2. London: Academic Press, 1980:225–94.
3. Willison K, Ashworth A. Mammalian spermatogenic gene expression. Trends Genet 1987;3:351–55.
4. Fauser BCJM, Hsueh AJ. Genetic basis of human reproductive endocrine disorders. Hum Reprod 1995;10:826–46.
5. Mak V, Jarvi KA. The genetics of male infertility. J Urol 1996;156:1245–57.