3World Health Organization. Termination of pregnancy with reduced doses of mifepfistone. World Health Organisation Task Force on Post-ovulatory Methods of Fertility Regulation. BMJ, 1993, 307 (6903) :532-537.
4Skafar DF. Differences in the bindling mechanism of RU486 and progesterone to the progesterone receptor. Biochemistry, 1991,30 (45) :10829-10832.