Print reference books do not check out and must be used in the Library. The purposes of using reference books are to
The Merck Manual of Diagnosis and Therapy (A.K.A. Merck's Manual)
There is also an online version Merck Manual Professional Version that you can utilize.
Human Diseases and Conditions
Professional Guide to Diseases
If you need to research a specific drug that is used to treat your disease, look for it in the PDR: