APA-referens (7:e uppl.)

Sommerville, D. M. Y. (1958). The elements of Non-Euclidean Geometry. Dover.

Chicago-referens (17:e uppl.)

Sommerville, Duncan M'Laren Young. The Elements of Non-Euclidean Geometry. Nueva York: Dover, 1958.

MLA-referens (9:e uppl.)

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