Cita APA (7a ed.)

Mc Kibben, E. G., Austin Griffin, R., & Hopkins, J. A. (1939). Changes in farm power and equipment: Field Implements. National Research ProyectWork Projects Administration.

Cita Chicago Style (17a ed.)

Mc Kibben, Eugene G., R. Austin Griffin, y John A. Hopkins. Changes in Farm Power and Equipment: Field Implements. Philadelphia: National Research ProyectWork Projects Administration, 1939.

Cita MLA (8a ed.)

Mc Kibben, Eugene G., et al. Changes in Farm Power and Equipment: Field Implements. National Research ProyectWork Projects Administration, 1939.