APA (7th ed.) Citation

Sommerville, D. M. Y. (1958). The elements of non-euclidean geometry. Dover Publications.

Chicago Style (17th ed.) Citation

Sommerville, Duncan M'Laren Young. The Elements of Non-euclidean Geometry. New York: Dover Publications, 1958.

MLA (9th ed.) Citation

Sommerville, Duncan M'Laren Young. The Elements of Non-euclidean Geometry. Dover Publications, 1958.