MLA
Billing, Archibald, 1791-1881. First principles of medicine. 1841. Medical Heritage Imprints Collection . Robert W. Woodruff Health Sciences Center. Library. https://digital.library.emory.edu/purl/006sxksq0m-cor.
APA, 6th edition
Billing, Archibald, 1791-1881. (1841)[First principles of medicine, 4th edition, revised and improved.]. Medical Heritage Imprints Collection , Robert W. Woodruff Health Sciences Center. Library. https://digital.library.emory.edu/purl/006sxksq0m-cor.
Chicago
Billing, Archibald, 1791-1881, First principles of medicine, 1841, Medical Heritage Imprints Collection , Robert W. Woodruff Health Sciences Center. Library. https://digital.library.emory.edu/purl/006sxksq0m-cor.