एपीए उद्धरण

Costain, T. B. (1960). The Chord of Steel: Alexander Graham Bell and the invention of the telephone. New York: Doubleday and Company.

शिकागो स्टाइल उद्धरण

Costain, Thomas B. The Chord of Steel: Alexander Graham Bell and the Invention of the Telephone. New York: Doubleday and Company, 1960.

एमएलए उद्धरण

Costain, Thomas B. The Chord of Steel: Alexander Graham Bell and the Invention of the Telephone. New York: Doubleday and Company, 1960.