Samuel, M.J.; Hart, R.H. 1998. Nitrogen fertilization, botanical composition and biomass production on mixed-grass rangeland. Journal of Range Management. 51(4): 408-416.

Samuel, M.J.; Hart, R.H. 1998. Nitrogen fertilization, botanical composition and biomass production on mixed-grass rangeland. Journal of Range Management. 51(4): 408-416.