एपीए उद्धरण

Keller, E. A. (1981). Environmental geology. Charles E Merrill.

शिकागो स्टाइल उद्धरण

Keller, Edward A. Environmental Geology. Columbus: Charles E Merrill, 1981.

एमएलए उद्धरण

Keller, Edward A. Environmental Geology. Charles E Merrill, 1981.