Douglas, D. (1959). Journal kept by David Douglas during his travels in North America, 1823-1827: Together with a particular description of thirty-three species of American oaks and eighteen species of Pinus, with appendices containing a list of the plants introduced by Douglas and an account of his death in 1834. Antiquarian Press.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Douglas, David. Journal Kept by David Douglas During His Travels in North America, 1823-1827: Together with a Particular Description of Thirty-three Species of American Oaks and Eighteen Species of Pinus, with Appendices Containing a List of the Plants Introduced by Douglas and an Account of His Death in 1834. London: Antiquarian Press, 1959.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Douglas, David. Journal Kept by David Douglas During His Travels in North America, 1823-1827: Together with a Particular Description of Thirty-three Species of American Oaks and Eighteen Species of Pinus, with Appendices Containing a List of the Plants Introduced by Douglas and an Account of His Death in 1834. Antiquarian Press, 1959.