एपीए उद्धरण

(1970). Contours of change. Washington, D.C: Argriculture.

शिकागो स्टाइल उद्धरण

Contours of Change. Washington, D.C: Argriculture, 1970.

एमएलए उद्धरण

Contours of Change. Washington, D.C: Argriculture, 1970.