Dyfyniad APA

(1990). 1990 Physicians' desk reference (44th ed.). Barnhart.

Dyfyniad Arddull Chicago

1990 Physicians' Desk Reference. 44th ed. New Jersey: Barnhart, 1990.

Dyfyniad MLA

1990 Physicians' Desk Reference. 44th ed. Barnhart, 1990.

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