Gaya APA

J., H., T., L., Vantrappen, G. (1984). Gastrointestinal Tract Disorders in The Elderly . New York: Churchill Livingstone Elsevier.

Gaya MLA

J., H., T., L., Vantrappen, G.. Gastrointestinal Tract Disorders in The Elderly. New York: Churchill Livingstone Elsevier, 1984. Text.