Ritter, William F. Agricultural nonpoint source pollution : watershed management and hydrology. Chapter 3 : Nitrogen and Water Quality / by William F. Ritter and Lars Bergstrom - Boca Raton, Florida: CRC Press, 2000 - 31 pages ISBN: 1-56670-222-4 Subjects--Topical Terms: NitrogenTechnology & EngineeringWater quality