APA

Erdman L. G., . (1950). The edge of time. New York: .

Chicago

Erdman Loula Grace, . 1950. The edge of time. New York: .

Harvard

Erdman L. G., . (1950). The edge of time. New York: .

MLA

Erdman Loula Grace, . The edge of time. New York: . 1950.