1. Ballantyne, A. B., Utah Agricultural Experiment Station Bulletin 143: 1 (1916).
2. Baver, L. D., Proceedings of the Soil Science Society of America 2: 75 (1938).
3. Plant Sociology 1932
4. Boynton, D., Cornell University Agricultural Experiment Station Bulletin 706: 1 (1938).
5. Buckingham, E., Bureau of Soils Bulletin 25: 1 (1904).