Chronic treatment of female rhesus monkeys with low doses of the antiprogestin ZK 137.316: establishment of a regimen that permits normal menstrual cyclicity - Zelinski-Wooten,M.B.; Slayden,O.D.; Chwalisz,K.; Hess,D.L.; Brenner,R.M.; Stouffer,R.L. (Hum Reprod, 1998)