APA

Keyser C. J., . (1926). Thinking about thinking. New York: Scripta mathematica.

Chicago

Keyser Cassius Jackson, . 1926. Thinking about thinking. New York: Scripta mathematica.

Harvard

Keyser C. J., . (1926). Thinking about thinking. New York: Scripta mathematica.

MLA

Keyser Cassius Jackson, . Thinking about thinking. New York: Scripta mathematica. 1926.