APA Style

Porter, R, S. et al (2008). The Merck Manual of Patient Symptoms : A Concise, Practical Guide to Etiology, Evaluation, and Treatment . West Point: Merck & Co.

MLA Style

Porter, Robert, S.. et al. "The Merck Manual of Patient Symptoms : A Concise, Practical Guide to Etiology, Evaluation, and Treatment". West Point: Merck & Co, 2008. print.