Harker, A. (1954). Petrology for students: An introduction to the study of rocks under the microscope (8th ed. rev.). University Press.
Chicago-viite (17. p.)Harker, Alfred. Petrology for Students: An Introduction to the Study of Rocks Under the Microscope. 8th ed. rev. Cambridge [Eng.]: University Press, 1954.
MLA-viite (8. p.)Harker, Alfred. Petrology for Students: An Introduction to the Study of Rocks Under the Microscope. 8th ed. rev. University Press, 1954.
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