Gaya APA

Heller, R, L., Swanson, C, P. (1962). Geology and earth sciences sourcebook for elementary and secondary ì schools . New York: New York: Holt, Rinehart and Winston; 1962.

Gaya MLA

Heller, Robert, L., Swanson, Carl, P.. "Geology and earth sciences sourcebook for elementary and secondary ì schools". New York: New York: Holt, Rinehart and Winston; 1962, 1962. Text.