United States. Forest Service. Northern Region. (1944). Early days in the forest service. U.S.D.A. Forest Service, Northern Region.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)United States. Forest Service. Northern Region. Early Days in the Forest Service. Missoula, Mont.: U.S.D.A. Forest Service, Northern Region, 1944.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)United States. Forest Service. Northern Region. Early Days in the Forest Service. U.S.D.A. Forest Service, Northern Region, 1944.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.