The Merck Manual of Diagnosis and Therapy 20th Edition is a comprehensive medical reference book published by Merck & Company, Incorporated. With a focus on clinical medicine, pathology, and internal medicine, this textbook covers a wide range of medical topics in-depth. The book features 3500 pages of valuable information in English, making it a trusted resource for healthcare professionals and students. With its detailed content and authoritative authorship, this manual is a valuable addition to any medical library.