APA

Irwin K. G., . (1966). The circle of days : measurement of time. New York: Bantam Books.

Chicago

Irwin Keith Gordon, . 1966. The circle of days : measurement of time. New York: Bantam Books.

Harvard

Irwin K. G., . (1966). The circle of days : measurement of time. New York: Bantam Books.

MLA

Irwin Keith Gordon, . The circle of days : measurement of time. New York: Bantam Books. 1966.