APA (7th ed.) Citation

Spence, H. J., Spence, K. D. M., Spence, H. J., & Spence, K. D. M. (1966). A guide to early Canadian glass. Longmans.

Chicago Style (17th ed.) Citation

Spence, Hilda Jennings, Kelvin D. M. Spence, Hilda Jennings Spence, and Kelvin D. M. Spence. A Guide to Early Canadian Glass. Don Mills: Longmans, 1966.

MLA (9th ed.) Citation

Spence, Hilda Jennings, et al. A Guide to Early Canadian Glass. Longmans, 1966.