APA Style

Chung, O. et al (1995). Textbook of Gastroenterology (2ndedtion). USA: J.B. Lippincott Compay.

MLA Style

Chung, Owyang. et al. "Textbook of Gastroenterology". 2ndedtion USA: J.B. Lippincott Compay, 1995. Text.