APA (7e ed.) Bronvermelding

Ogundipe P. A. & Tregidgo P. S. (1974). Practical English: A comprehensive secondary course. Book four. Longman.

Chicago (17e ed.) Bronvermelding

Ogundipe P. A. en Tregidgo P. S. Practical English: A Comprehensive Secondary Course. Book Four. England: Longman, 1974.

MLA (9e ed.) Bronvermelding

Ogundipe P. A. en Tregidgo P. S. Practical English: A Comprehensive Secondary Course. Book Four. Longman, 1974.