Richardson, W. B., Strauss, E. A., Monroe, E. M., Bartsch, L. A., Cavanaugh, J.
C., Vingum, L., and Soballe, D., 2004, Denitrification in the Upper Mississippi
River: rates, controls, and contribution to nitrate flux: Canadian Journal of
Fisheries and Aquatic Sciences, v. 61, p. 1102 1112.