APA (7th ed.) Citation

Sommerville, D. (1958). The elements of non-Euclidean geometry. Dover Publications, Inc.

Chicago Style (17th ed.) Citation

Sommerville, D.M.Y. The Elements of Non-Euclidean Geometry. New York, New York: Dover Publications, Inc, 1958.

MLA (9th ed.) Citation

Sommerville, D.M.Y. The Elements of Non-Euclidean Geometry. Dover Publications, Inc, 1958.