APA (7th ed.) Citation

(1988). Ufo's:where do they come from?: Contemporary theories on the origin of the phenomenon. Orbis publishing.

Chicago Style (17th ed.) Citation

Ufo's:where Do They Come from?: Contemporary Theories on the Origin of the Phenomenon. Orbis publishing, 1988.

MLA (9th ed.) Citation

Ufo's:where Do They Come from?: Contemporary Theories on the Origin of the Phenomenon. Orbis publishing, 1988.

Warning: These citations may not always be 100% accurate.