TY  - RPRT
TI  - Changes in the chemistry of precipitation in the United States, 1981-1998
AU  - M.A. Nilles
AU  - B.E. Conley
PY  - 2001
DO  - 10.1023/a:1013889302895
UR  - https://pubs.usgs.gov/publication/70023032
ID  - 70023032
ER  -