Gaya APA

Gershman, G., Thomson, M. (2012). Practical pediatric gastrointestinal endoscopy (2nd ed). U.S.A: Wile-Bleckwell.

Gaya MLA

Gershman, George., Thomson, Mike. "Practical pediatric gastrointestinal endoscopy". 2nd ed U.S.A: Wile-Bleckwell, 2012. Text.