Agronomy in the Americas Denver, C., American Society of Agronomy., Roberts, L. M., Murphy, R. P., Crowder, L. V., Rigney, J. A., . . . stelly, M. (1964). Articles of the annual meeting. Wisconsin, Estados Unidos: American Society of Agronomy.

Agronomy in the Americas Denver, Colorado, American Society of Agronomy, Lewis M. Roberts, R. P. Murphy, L. V. Crowder, J. A. Rigney, H. L. Hamilton, and Matthias stelly. Articles of the Annual Meeting. Wisconsin, Estados Unidos: American Society of Agronomy, 1964.

Agronomy in the Americas Denver, Colorado, et al. Articles of the Annual Meeting. Wisconsin, Estados Unidos: American Society of Agronomy, 1964.