APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

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

MLA (9th ed.) Citation

Sommerville, D.M.Y. The Elements of Non-euclidean Geometry. Dover, 1958.