APA

robert . j f., . (1983). General Geology. london: columbus merrill puplishing co.

Chicago

robert . j foster, . 1983. General Geology. london: columbus merrill puplishing co.

Harvard

robert . j f., . (1983). General Geology. london: columbus merrill puplishing co.

MLA

robert . j foster, . General Geology. london: columbus merrill puplishing co. 1983.