4) Beauchamp, E.G., Trevors, J.T. and Paul, J.W. (1989) Carbon sources for bacterial denitrification, Advances in Soil Science, 10, 113-142.
5) Loehr, R.C., Jewell, W.J., Novak, J.D., Clarkson, W.W. and Friedman, G.S. (1979) Land Application of Wastes, Vol. II, Van Nostrand Reinhold Company.