Style de citation APA (7e éd.)

Weldon, J., & Levitt, Z. (1975). UFO's: What on earth is happening? Harvest House Publishers.

Style de citation Chicago (17e éd.)

Weldon, John, et Zola Levitt. UFO's: What on Earth Is Happening? Irvine, Calif: Harvest House Publishers, 1975.

Style de citation MLA (9e éd.)

Weldon, John, et Zola Levitt. UFO's: What on Earth Is Happening? Harvest House Publishers, 1975.