Washington Native Plant Society. (1983). Douglasia occasional papers. The Society.
Style de citation Chicago (17e éd.)Washington Native Plant Society. Douglasia Occasional Papers. [Seattle, Wash.]: The Society, 1983.
Style de citation MLA (8e éd.)Washington Native Plant Society. Douglasia Occasional Papers. The Society, 1983.
Attention : ces citations peuvent ne pas être correctes à 100%.