Cita APA (7a ed.)

Loeb, A., & Petkoff, R. (2021). Extraterrestrial: The first sign of intelligent life beyond earth (Unabridged.). HarperAudio.

Cita Chicago Style (17a ed.)

Loeb, Avi, y Robert Petkoff. Extraterrestrial: The First Sign of Intelligent Life Beyond Earth. Unabridged. New York: HarperAudio, 2021.

Cita MLA (8a ed.)

Loeb, Avi, y Robert Petkoff. Extraterrestrial: The First Sign of Intelligent Life Beyond Earth. Unabridged. HarperAudio, 2021.

Precaución: Estas citas no son 100% exactas.