APA

Gans D., . (1973). An introduction to non-Euclidean geometry. New York: Academic Press.

Chicago

Gans David, . 1973. An introduction to non-Euclidean geometry. New York: Academic Press.

Harvard

Gans D., . (1973). An introduction to non-Euclidean geometry. New York: Academic Press.

MLA

Gans David, . An introduction to non-Euclidean geometry. New York: Academic Press. 1973.