1. Some effects of crop-production technology on environmental quality;ALDRICH;Bioscience.,1972
2. Agriculture and the Quality of Our Environment;BRADY,1967
3. Isotopic tracer techniques for identification of sources of nitrate pollution;EDWARDS;J. Environ. Quality,1973
4. Use of variation in natural nitrogen isotope abundance for environmental studies: a questionable approach;HAUCK;Science,1972
5. Nitrate concentrations in streams near Alliston, Ontario, as influenced by nitrogen fertilization of adjacent fields;HILL;J. Soil and Water Conserv.,1974