APA Citatie

Howard, E. R., & Whimster, W. F. (1976). Benign rectal ulceration of unknown origin. An unusual cause of rectal bleeding.

Chicago Style citaat

Howard, E R., en W F. Whimster. Benign Rectal Ulceration of Unknown Origin. An Unusual Cause of Rectal Bleeding. 1976.

MLA citatie

Howard, E R., en W F. Whimster. Benign Rectal Ulceration of Unknown Origin. An Unusual Cause of Rectal Bleeding. 1976.