1. Alberts EE, Spomer RG (1985) NO3−N movement in deep loess soils. American Society of Agricultural Engineers, St Joseph, MI
2. Alexander M (1977) Introduction to soil microbiology, 2nd edn. Wiley, New York
3. Aley T (1977) A Model for relating land use and groundwater quality in Southern Missouri. In: Dilamarter RR, Csallany SC (eds) Hydrologic problems in Karst regions. Western Kentucky University, Bowling Green, Kentucky
4. Bobier MW, Frank KD, Spalding RF (1993) Nitrate-N movement in a fine-textured vadose zone. J Soil Water Conserv 48(4):350–353
5. Campbell GS (1985) Soil physics with BASIC: transport models for soil–plant systems. Elsevier, New York