Dyfyniad APA

Firestein, G. S., & Kelley, W. N. (2013). Kelley's textbook of rheumatology (9th ed.). Elsevier/Saunders.

Dyfyniad Arddull Chicago

Firestein, Gary S., and William N. Kelley. Kelley's Textbook of Rheumatology. 9th ed. Philadelphia, PA: Elsevier/Saunders, 2013.

Dyfyniad MLA

Firestein, Gary S., and William N. Kelley. Kelley's Textbook of Rheumatology. 9th ed. Elsevier/Saunders, 2013.

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