APA

Mattersdorf L., . (1962). A key to the heavens. New York: [s.n.].

Chicago

Mattersdorf Leo, . 1962. A key to the heavens. New York: [s.n.].

Harvard

Mattersdorf L., . (1962). A key to the heavens. New York: [s.n.].

MLA

Mattersdorf Leo, . A key to the heavens. New York: [s.n.]. 1962.