Knox, P. L. (1964). Wonder worlds. The Voice Prophecy.
Cita Chicago (17th ed.)Knox, Phillip L. Wonder Worlds. The Voice Prophecy, 1964.
Cita MLA (9th ed.)Knox, Phillip L. Wonder Worlds. The Voice Prophecy, 1964.
Atenció: Aquestes cites poden no estar 100% correctes.