Keller, E. A. (2011). Environmental geology (9th ed.). Prentice Hall.
Chicago Style aipamenaKeller, Edward A. Environmental Geology. 9th ed. Boston: Prentice Hall, 2011.
MLA aipamenaKeller, Edward A. Environmental Geology. 9th ed. Prentice Hall, 2011.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.