Judson, S., Kauffman, M. E., & Leet, L. D. (1987). Physical geology (7th ed.). Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Judson, Sheldon, Marvin Earl Kauffman, agus L. Don Leet. Physical Geology. 7th ed. Englewood Cliffs, N.J: Prentice-Hall, 1987.
Lua MLA (9ú heag.)Judson, Sheldon, et al. Physical Geology. 7th ed. Prentice-Hall, 1987.
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