Washington Native Plant Society. (1983). Douglasia occasional papers. The Society.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रWashington Native Plant Society. Douglasia Occasional Papers. [Seattle, Wash.]: The Society, 1983.
एमएलए (8वां संस्करण) प्रशस्ति पत्रWashington Native Plant Society. Douglasia Occasional Papers. The Society, 1983.
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