Dyfyniad APA

Hulley, S. B., & Cummings, S. R. (1988). Designing clinical research: An epidemiologic approach. Williams & Wilkins.

Dyfyniad Arddull Chicago

Hulley, Stephen B., and Steven R. Cummings. Designing Clinical Research: An Epidemiologic Approach. Baltimore: Williams & Wilkins, 1988.

Dyfyniad MLA

Hulley, Stephen B., and Steven R. Cummings. Designing Clinical Research: An Epidemiologic Approach. Williams & Wilkins, 1988.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.