 | Agricultural productivity Colombia. | (2) |
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 | Changes in agricultural production and technology in Colombia / . Atkinson, L. Jay, 1913- 1n Washington, D.C. : U.S. Dept. of Agriculture, Economic Research Service in cooperation with the Ministry of Agriculture and the Central Planning Agency of Colombia, 1969. | |
 | Agricultural productivity in Colombia / . Atkinson, L. Jay, 1913- 1n Washington, D.C. : U.S. Dept. of Agriculture, Economic Research Service in cooperation with the Ministry of Agriculture and the National Department of Planning of Colombia, 1970. | |
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