Cita APA (7th ed.)

Gilbert, C. M., & Christensen, M. N. j. a. (1967). Physical geology: Laboratory course (2nd ed.). McGraw-HIll.

Cita Chicago (17th ed.)

Gilbert, Charles Mervin, i Mark N. jt. author Christensen. Physical Geology: Laboratory Course. 2nd ed. New York: McGraw-HIll, 1967.

Cita MLA (9th ed.)

Gilbert, Charles Mervin, i Mark N. jt. author Christensen. Physical Geology: Laboratory Course. 2nd ed. McGraw-HIll, 1967.