Gaya APA

Starhler, A, N., Swanson, C, P. (1972). Planet earth its physical systems through geologic time . New York: New York: Harper & Row; 1972.

Gaya MLA

Starhler, Arthur, N., Swanson, Carl, P.. "Planet earth its physical systems through geologic time". New York: New York: Harper & Row; 1972, 1972. Text.