APA (7th ed.) Citation

Ewer, D. W., Hall, J. B., & Clerk, G. C. (1972). Ecological biology: For A-level and intermediate students in Africa. Longman.

Chicago Style (17th ed.) Citation

Ewer, D. W., John Bartholomew Hall, and G. C. Clerk. Ecological Biology: For A-level and Intermediate Students in Africa. London: Longman, 1972.

MLA (9th ed.) Citation

Ewer, D. W., et al. Ecological Biology: For A-level and Intermediate Students in Africa. Longman, 1972.