एपीए उद्धरण

Pledge H.T. (1947). Science Since 1500 (1947.). Philosophical Library.

शिकागो स्टाइल उद्धरण

Pledge H.T. Science Since 1500. 1947. [s.l]: Philosophical Library, 1947.

एमएलए उद्धरण

Pledge H.T. Science Since 1500. 1947. Philosophical Library, 1947.