एपीए उद्धरण

Spencer, E. W. (2003). Earth science: Understanding environmental systems. McGraw-Hill.

शिकागो स्टाइल उद्धरण

Spencer, Edgar Winston. Earth Science: Understanding Environmental Systems. McGraw-Hill, 2003.

एमएलए उद्धरण

Spencer, Edgar Winston. Earth Science: Understanding Environmental Systems. McGraw-Hill, 2003.