This is the zero-volume set of "Harrison's Principles of Internal Medicine, Vol. 1 and 2; 18th Edition," a comprehensive textbook authored by Stephen L. Hauser, J. Larry Jameson, Anthony S. Fauci, Dan L. Longo, and Dennis L. Kasper. Published by McGraw-Hill Professional Publishing in 2012, these reference books cover all aspects of internal medicine. With a total of 4012 pages, the book is designed for adult and further education in the medical field, providing in-depth knowledge on various medical topics.