Não informado. (1945). Down to earth: A review of agricultural chemical progress. Down Chemical, Agricultural Products Department.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Não informado. Down to Earth: A Review of Agricultural Chemical Progress. Midland, Mich: Down Chemical, Agricultural Products Department, 1945.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Não informado. Down to Earth: A Review of Agricultural Chemical Progress. Down Chemical, Agricultural Products Department, 1945.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.