Oettel, M. & Kurischko, A. (1980): STS 557, a new orally active progestin with antiprogestational and contragestational properties in rabbits. In: Contraception. 21(1):61-69. PMID 7357870, doi:10.1016/0010-7824(80)90140-7.
Oettel, M. & Kurischko, A. (1980): STS 557, a new orally active progestin with antiprogestational and contragestational properties in rabbits. In: Contraception. 21(1):61-69. PMID 7357870, doi:10.1016/0010-7824(80)90140-7.