एपीए उद्धरण

Burkhardt Frederick. (1996). Charles Darwin's letters: A selection 1825-1859. CUP.

शिकागो स्टाइल उद्धरण

Burkhardt Frederick. Charles Darwin's Letters: A Selection 1825-1859. Cambridge: CUP, 1996.

एमएलए उद्धरण

Burkhardt Frederick. Charles Darwin's Letters: A Selection 1825-1859. CUP, 1996.