1. L. G. Wall, J. Plant Growth Regul. 19, 167 (2000).
2. J. O. Dawson, G. J. Gotfrid, and D. Hahn, “Occurrence, Structure, and Nitrogen-fixation of Root Nodules of Actinorhizal Arizona Alder,” in USDA Forest Service Proceedings RMRS-P-36 (2005), pp. 75–79.
3. J. O. Dawson, Outlook on Agriculture 15, 202 (1986).
4. R. O. D. Dixon and C. T. Wheeler, Nitrogen Fixation in Plants (Chapman and Hall, New York, 1986).
5. D. E. Hibbs and J. K. Cromack, in Biology of Frankia and Actinorhizal Plants (Academic Press, New York, 1990), pp. 343–363.