Washington State Planning Council & United States. National Park Service. (1941). A study of parks, parkways, and recreational areas.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Washington State Planning Council و United States. National Park Service. A Study of Parks, Parkways, and Recreational Areas. [Olympia, 1941.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Washington State Planning Council و United States. National Park Service. A Study of Parks, Parkways, and Recreational Areas. 1941.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.