title: [Confused clinical problems of combined oral contraceptives].
authors: Email: lijian02@hotmail.com.
authors: Jian
authors: J
authors: Li
authors: Guangsheng
authors: G
authors: Fan
authors: Ling
authors: L
authors: Xu
mesh_terms: D003277:Contraceptives, Oral, Combined; D005260:Female; D006801:Humans; D011372:Progestins; D012307:Risk Factors
chemical_list: D003277:Contraceptives, Oral, Combined; D011372:Progestins