TY  - RPRT
TI  - Trend analysis of sulfate, nitrate and pH data collected at National Atmospheric Deposition Program/National Trends Network stations between 1980 and 1991
AU  - W.G. Baier
AU  - T.A. Cohn
PY  - 1993
DO  - 10.3133/ofr9356
UR  - https://pubs.usgs.gov/publication/ofr9356
ID  - ofr9356
ER  -