Gloria, R. T. (1977). Comparative performance of three grain sorghum (Sorghum bicolor L. Moench) cultivars grown under rubber and in the open field as affected by nitrogen level and plant density. University of the Philippines Library.

Gloria, Ricardo Tumanda. Comparative Performance of Three Grain Sorghum (Sorghum Bicolor L. Moench) Cultivars Grown Under Rubber and in the Open Field as Affected by Nitrogen Level and Plant Density. Quezon City: University of the Philippines Library, 1977.

Gloria, Ricardo Tumanda. Comparative Performance of Three Grain Sorghum (Sorghum Bicolor L. Moench) Cultivars Grown Under Rubber and in the Open Field as Affected by Nitrogen Level and Plant Density. University of the Philippines Library, 1977.