Nisbet, J. (2012). David Douglas: A naturalist at work : an illustrated exploration across two centuries in the Pacific Northwest. Sasquatch Books.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Nisbet, Jack. David Douglas: A Naturalist at Work : An Illustrated Exploration Across Two Centuries in the Pacific Northwest. Seattle, WA: Sasquatch Books, 2012.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Nisbet, Jack. David Douglas: A Naturalist at Work : An Illustrated Exploration Across Two Centuries in the Pacific Northwest. Sasquatch Books, 2012.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.