Erickson, J. (1992). An Introduction to Fossils and Minerals: Seeking Clues to the Earth's Past. Facts on File.
Chicago-referens (17:e uppl.)Erickson, Jon. An Introduction to Fossils and Minerals: Seeking Clues to the Earth's Past. New York: Facts on File, 1992.
MLA-referens (9:e uppl.)Erickson, Jon. An Introduction to Fossils and Minerals: Seeking Clues to the Earth's Past. Facts on File, 1992.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.