United States. Forest Service. North Pacific Region. Public Relations Office. (1932). What is forestry?: An outline for classes in economics, geography and nature study in high schools of Washington.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)United States. Forest Service. North Pacific Region. Public Relations Office. What Is Forestry?: An Outline for Classes in Economics, Geography and Nature Study in High Schools of Washington. Portland, 1932.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)United States. Forest Service. North Pacific Region. Public Relations Office. What Is Forestry?: An Outline for Classes in Economics, Geography and Nature Study in High Schools of Washington. 1932.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.