APA
Pitkin R. M., . (1985). The year book of obstetrics and gynecology. Chicago: Year Book Medical.
Chicago
Pitkin Roy M, . 1985. The year book of obstetrics and gynecology. Chicago: Year Book Medical.
Harvard
Pitkin R. M., . (1985). The year book of obstetrics and gynecology. Chicago: Year Book Medical.
MLA
Pitkin Roy M, . The year book of obstetrics and gynecology. Chicago: Year Book Medical. 1985.