APA

Vardeman R. E., Copyright Paperback Collection (Library of Congress), . (1983). The sorcerer's skull. New York: Ace Science Fiction Books.

Chicago

Vardeman Robert E, Copyright Paperback Collection (Library of Congress), . 1983. The sorcerer's skull. New York: Ace Science Fiction Books.

Harvard

Vardeman R. E., Copyright Paperback Collection (Library of Congress), . (1983). The sorcerer's skull. New York: Ace Science Fiction Books.

MLA

Vardeman Robert E, Copyright Paperback Collection (Library of Congress), . The sorcerer's skull. New York: Ace Science Fiction Books. 1983.