APA

Clarke A. C., . (1968). The promise of space. New York: Harper & Row.

Chicago

Clarke Arthur Charles, . 1968. The promise of space. New York: Harper & Row.

Harvard

Clarke A. C., . (1968). The promise of space. New York: Harper & Row.

MLA

Clarke Arthur Charles, . The promise of space. New York: Harper & Row. 1968.