The history of medical literature, publishing, and libraries has traditionally played a strong role in the history of medicine, especially in the twentieth century when numerous retrospective guides have supported its study. The most important of these guides, Leslie T. Morton's A Medical bibliography (Garrison and Morton): An Annotated Check List of Texts Illustrating the History of Medicine, has become a classic work used extensively by booksellers, collectors, and others interested in medical literature. Other guides generally supplement “Garrison-Morton” through their much narrower geographical or chronological focus: for example, Francisco Guerra's American Medical Bibliography 1639–1783; Robert Austin’s Early American Medical Imprints 1668–1820; and Francesco Cordasco's American Medical Imprints 1820-1910. Added to these are descriptive catalogues of important library collections such as the Index-Catalogue of the Library of the Surgeon General's Office (1880–1961), William Osler's Bibliotheca Osleriana: A Catalogue of Books Illustrating the History of Medicine and Science, and Bibliotheca Walleriana. As well, numerous studies of medical literature have appeared, perhaps the most notable being John L. Thornton's Medical Books, Libraries and Collectors. Both Thornton's book and the Gadson-Morton bibliography have recently been revised and republished in new editions. Another publication, Francesco Cordasco's Medical Publishing in 19th Century America, also merits attention as a recent contribution to the history of medical literature.