APA (7th ed.) Citation

(1981). The World almanac and book of facts 1981. World Almanac Books.

Chicago Style (17th ed.) Citation

The World Almanac and Book of Facts 1981. New York: World Almanac Books, 1981.

MLA (9th ed.) Citation

The World Almanac and Book of Facts 1981. World Almanac Books, 1981.

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