एपीए उद्धरण

Longwell, C. R., & Flint, R. F. Introduction to physical geology (6th ed.).

शिकागो स्टाइल उद्धरण

Longwell, Chester R., और Richard F. Flint. Introduction to Physical Geology. 6th ed.

एमएलए उद्धरण

Longwell, Chester R., और Richard F. Flint. Introduction to Physical Geology. 6th ed.