Huffman, Wallace E.; Yee, J.; Ahearn, M.; Newson, M. - Department of Economics, Iowa State University - 2002
Yee, J., W.E. Huffman, M. Ahearn, and M. Newson. "Sources of Agricultural Productivity Growth at the State Level, 1960-1993," V. Eldon Ball and G. Norton, eds. Agricultural Productivity: Measurement and Sources of Growth. Kluwer Academic Press, 2002, pp. 185-210.
