This book, "Epidemiology and public health a text and reference book for physicians, medical students and health workers. pt. 521", by Victor C. Vaughan, is a replication of a book originally published before 1922. It has been restored by human beings, page by page, so that you may enjoy it in a form as close to the original as possible. This book was created using print-on-demand technology. Thank you for supporting classic literature.