APA

Spengler O., . (1926). The decline of the West. New York: Knopf.

Chicago

Spengler Oswald, . 1926. The decline of the West. New York: Knopf.

Harvard

Spengler O., . (1926). The decline of the West. New York: Knopf.

MLA

Spengler Oswald, . The decline of the West. New York: Knopf. 1926.