National Library of Medicine classification :
a scheme for the shelf arrangement of books in the field of medicine and its related sciences.
APA Citation
National Library of Medicine (U.S.). (1981). National Library of Medicine classification: a scheme for the shelf arrangement of books in the field of medicine and its related sciences. 4th ed., rev. Bethesda, Md.: The Library.
MLA Citation
National Library of Medicine (U.S.). National Library of Medicine Classification: a Scheme for the Shelf Arrangement of Books In the Field of Medicine And Its Related Sciences. 4th ed., rev. Bethesda, Md.: The Library, 1981.
Warning: These citations may not always be complete (especially for serials).