This site links to the diagnostic and care manuals published by Marck & Co. Available free online are the following: * Patients and Caregivers 1. The Merck Manual - Home Edition -- Medical reference aimed at the average person interested in health and disease. 2. The Merck Manual of Health and Aging -- Comprehensive guide to the changes and challenges of aging, aimed at the average reader. * Health Care Professionals 1. The Merck Manual of Diagnosis and Therapy -- For over 100 years, the most widely used handbook of symptoms and therapies for medical professionals. 2. The Merck Manual of Geriatrics -- Geriatric medicine and care of the elderly. * Veterinarians 1. The Merck Veterinary Manual -- Comprehensive source on animal healthcare for veterinary professionals.