1Moayad B Z. Agricultural and mechanization status in USA [J] International Agricultural Engineering Jour- nal, 2014 (1): 35-44.
2Yang D T. Knowledge spillovers and labor assignments of the farm household [D] . Chicago: The University of Chicago, 2013.
3Gajendra S, Pathak B K. A decision support system for mechanical harvesting and transportation of sugarcane in Thailand [J] . Computers and Electronics in Agricul- ture, 2014 (11): 173-182.