ISBN 978-0-313-21221-5. delRey, Lester. The World of Science Fiction: 1926–1976: The History of a Subculture. New York: DelRey Books. 1979 [2020-09-26]
Fiction. New York: St. Martin's Press, Inc. 1993. ISBN 0-312-09618-6. delRey, Lester. The World of Science Fiction: 1926–1976: The History of a Subculture