Cita APA (7th ed.)
Conklin, G. 12 Great Classics of Science Fiction. Fawcett Gold Medal.
Cita Chicago (17th ed.)
Conklin, Groff. 12 Great Classics of Science Fiction. Greenwich, EUA: Fawcett Gold Medal.
Cita MLA (9th ed.)
Conklin, Groff. 12 Great Classics of Science Fiction. Fawcett Gold Medal.
Atenció: Aquestes cites poden no estar 100% correctes.