Caldwell, B. E., Schillinger, J. A., Barton, J. H., Qualset, C. O., Duvick, D. N., & Barnes, R. F. (1989). Intellectual property rights associated with plants. Wisconsin, Estados Unidos de América: Crop Science Society of America, Inc. ; American Society of Agronomy, Inc., Soil Science Society of America, Inc..

Caldwell, B. E.,, J. A. Schillinger, J. H. Barton, C. O. Qualset, D. N. Duvick, and R. F. Barnes. Intellectual Property Rights Associated With Plants. Wisconsin, Estados Unidos de América: Crop Science Society of America, Inc. ; American Society of Agronomy, Inc., Soil Science Society of America, Inc., 1989.

Caldwell, B. E.,, et al. Intellectual Property Rights Associated With Plants. Wisconsin, Estados Unidos de América: Crop Science Society of America, Inc. ; American Society of Agronomy, Inc., Soil Science Society of America, Inc., 1989.