APA (7e ed.) Bronvermelding

Pritchard, J. A., MacDonald, P. C. 1., & Williams, J. W. 1. 1. (1976). Williams Obstetrics (15th ed.). Cardinal Book Store.

Chicago (17e ed.) Bronvermelding

Pritchard, Jack A., Paul C. 1930 MacDonald, en John Whiteridge 1866- 1931 Williams. Williams Obstetrics. 15th ed. Manila: Cardinal Book Store, 1976.

MLA (9e ed.) Bronvermelding

Pritchard, Jack A., et al. Williams Obstetrics. 15th ed. Cardinal Book Store, 1976.