title: Allene versus acetylene in progestational steroids.
mesh_terms: D000114:Acetylene; D003276:Contraceptives, Oral / Q000138:chemical synthesis*; D004967:Estrogens; D013739:Testosterone / Q000138:chemical synthesis*
chemical_list: D003276:Contraceptives, Oral; D004967:Estrogens; D013739:Testosterone; D000114:Acetylene