APA Style

Ahlgren, J, D., S., M, J. (1992). Gastrointestinal oncology . , Philadelphia,: J.B. Lippincott Co.

MLA Style

Ahlgren, James, D.., S., Macdonald, John. "Gastrointestinal oncology". , Philadelphia,: J.B. Lippincott Co, 1992. Text.