Não informado. West Virginia Agriculture and Forestry. University of West Virginia, College of Agriculture and Forestry.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Não informado. West Virginia Agriculture and Forestry. Morgantown, Wa. Va: University of West Virginia, College of Agriculture and Forestry.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Não informado. West Virginia Agriculture and Forestry. University of West Virginia, College of Agriculture and Forestry.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.