एपीए उद्धरण

Hettner, A. (1972). Surface features of the land: Problems and methods of geomorphology. Macmillan.

शिकागो स्टाइल उद्धरण

Hettner, Alfred. Surface Features of the Land: Problems and Methods of Geomorphology. London: Macmillan, 1972.

एमएलए उद्धरण

Hettner, Alfred. Surface Features of the Land: Problems and Methods of Geomorphology. Macmillan, 1972.