APA (7th ed.) Citation

Howells, M. F., Leveridge, B. E., & Reedman, A. J. (1981). Snowdonia. Unwin Paperbacks.

Chicago Style (17th ed.) Citation

Howells, Malcolm F., B. E. Leveridge, and A. J. Reedman. Snowdonia. London: Unwin Paperbacks, 1981.

MLA (9th ed.) Citation

Howells, Malcolm F., et al. Snowdonia. Unwin Paperbacks, 1981.