Não informado. (2016). Research Program on Soils of the Tropics, Annual Report. North Carolina State University, Soil Science Department.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Não informado. Research Program on Soils of the Tropics, Annual Report. Raleigh, NC: North Carolina State University, Soil Science Department, 2016.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Não informado. Research Program on Soils of the Tropics, Annual Report. North Carolina State University, Soil Science Department, 2016.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.