@book{8887,
	author = {Tolley, H. R. and Humphries, W. R.},
	title = {Tractors and horses in the winter wheat belt,},
	publisher = {Govt. print off.,},
	year = {1924.},
	series = {United States. Dept. of agriculture.},
	address = {Washington,},
	note = {Joint contribution from Bureau of public roads, Bureau of agricultural economics, Bureau of animal industry.}
}