Christensen, J. R. (1981). A field guide to the butterflies of the Pacific Northwest. University Press of Idaho.
Style de citation Chicago (17e éd.)Christensen, James R. A Field Guide to the Butterflies of the Pacific Northwest. Moscow, Idaho: University Press of Idaho, 1981.
Style de citation MLA (8e éd.)Christensen, James R. A Field Guide to the Butterflies of the Pacific Northwest. University Press of Idaho, 1981.
Attention : ces citations peuvent ne pas être correctes à 100%.