Fichter, L. S., & Farmer, G. T. (1991). Earth materials and earth processes: An introduction (3rd ed.). Macmillan.
Lua i Stíl Chicago (17ú heag.)Fichter, Lynn S., agus G. Thomas Farmer. Earth Materials and Earth Processes: An Introduction. 3rd ed. New York: Macmillan, 1991.
Lua MLA (9ú heag.)Fichter, Lynn S., agus G. Thomas Farmer. Earth Materials and Earth Processes: An Introduction. 3rd ed. Macmillan, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.