Pope, C. A., & Heady, E. O. (1982). The effects of technological progress and weather on corn belt crop yields. Ames: Center for Agricultural and Rural Development. Iowa State University.
Παραπομπή Chicago StylePope, C. Arden, and Earl O. Heady. The Effects of Technological Progress and Weather On Corn Belt Crop Yields. Ames: Center for Agricultural and Rural Development. Iowa State University, 1982.
Παραπομπή MLAPope, C. Arden, and Earl O. Heady. The Effects of Technological Progress and Weather On Corn Belt Crop Yields. Ames: Center for Agricultural and Rural Development. Iowa State University, 1982.
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