Cita APA (7a ed.)

Olmstead, A. L., & Rhode, P. W. (2000). The diffusion of the tractor in American agriculture, 1910-60. National Bureau of Economic Research.

Cita Chicago Style (17a ed.)

Olmstead, Alan L., y Paul Webb Rhode. The Diffusion of the Tractor in American Agriculture, 1910-60. Cambridge, MA: National Bureau of Economic Research, 2000.

Cita MLA (9a ed.)

Olmstead, Alan L., y Paul Webb Rhode. The Diffusion of the Tractor in American Agriculture, 1910-60. National Bureau of Economic Research, 2000.