1. Slow release N fertilizers applied in fall for corn;Beauchamp;Can. J. Soil Sci.,1977
2. Biggar, J. W., and Corey, R. B. 1969. Agricultural drainage and eutrophication, pp. 405-445. In Eutrophication, causes, consequences and correctives. Proc. Symp. Nat. Acad. Sci., Washington, D. C.
3. Quality of water discharged from two agricultural watersheds in Southwestern Iowa;Burwell;Water Resour. Res.,1974
4. Nitrogen in subsurface discharge from agricultural watersheds;Burwell;J. Environ. Qual.,1976
5. Agriculture's contribution to the fertilization of Canal Lake;Campbell;J. Soil Water Conserv.,1969