Rogin, L. (1931). The introduction of farm machinery in its relation to the productivity of labor in the agriculture of the United States during the nineteenth century. Berkeley, Calif.: University of California Press.

Rogin, Leo. The Introduction of Farm Machinery in Its Relation to the Productivity of Labor in the Agriculture of the United States During the Nineteenth Century. Berkeley, Calif.: University of California Press, 1931.

Rogin, Leo. The Introduction of Farm Machinery in Its Relation to the Productivity of Labor in the Agriculture of the United States During the Nineteenth Century. Berkeley, Calif.: University of California Press, 1931.