Dyfyniad APA

(1987). National library of medicine current catalog. Maryland: National Library of Medicine.

Dyfyniad Arddull Chicago

National Library of Medicine Current Catalog. Maryland: National Library of Medicine, 1987.

Dyfyniad MLA

National Library of Medicine Current Catalog. Maryland: National Library of Medicine, 1987.

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