APA (7th ed.) Citation

Spencer,John. (1992). World atlas of ufo's: Sightings,abductions and close encounters. Smithmark publishers inc..

Chicago Style (17th ed.) Citation

Spencer,John. World Atlas of Ufo's: Sightings,abductions and Close Encounters. New York: Smithmark publishers inc., 1992.

MLA (9th ed.) Citation

Spencer,John. World Atlas of Ufo's: Sightings,abductions and Close Encounters. Smithmark publishers inc., 1992.

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