Cruz, W. D. (1987). The environmental effects of soil erosion: Economic valuation issues for Philippine uplands. College of Economics and Management, University of the Philippines at Los Baños.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Cruz, Wilfrido D. The Environmental Effects of Soil Erosion: Economic Valuation Issues for Philippine Uplands. College, Laguna: College of Economics and Management, University of the Philippines at Los Baños, 1987.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Cruz, Wilfrido D. The Environmental Effects of Soil Erosion: Economic Valuation Issues for Philippine Uplands. College of Economics and Management, University of the Philippines at Los Baños, 1987.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.