1. JD Aber, KJ Nadelhoffer, P. Steudler, and JM Melillo .1989 .Nitrogen saturation in northern forest ecosystems .Bioscience,39:378 -86 .
2. R. Aerts, and F. Berendse .1988 .The effect of increased nutrient availability on vegetation dynamics in wet heathlands .Vegetatio,76:63 -69 .
3. GD Agrawal, SK Lunkad, and T. Malkhed .1999 .Diffuse agricultural nitrate pollution of groundwaters in India .Water Sci Technol,39:67 -75 .
4. GI Agren, and E. Bosatta .1988 .Nitrogen saturation of terrestrial ecosystems .Environ Pollut,54:185 -97 .
5. WR Beisel .1982 .Synergism and antagonism of parasitic diseases and malnutrition .Rev Infect Dis,4:746 -50 .