Fadavi, R. ., A. . Keyhani, and S. S. . Mohtasebi. “Estimation of a Mechanization Index and Its Impact on Energy and Economic Factors in Apple Orchard in Iran”. Asian Journal of Agriculture and Rural Development, vol. 2, no. 2, June 2012, pp. 248-59, http://archive.aessweb.com/index.php/5005/article/view/556.