Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) I Spitz,The use of progesterone antagonists and progesterone receptor modulators in contraception,Steroids,0039-128X,Elsevier BV,2000-11,65,10-11,817-823,https://cir.nii.ac.jp/crid/1360011145423968256,https://doi.org/10.1016/s0039-128x(00)00199-9