TY  - RPRT
TI  - An evaluation of trends in the acidity of precipitation and the related acidification of surface water in North America
AU  - John T. Turk
PY  - 1983
DO  - 10.3133/wsp2249
UR  - https://pubs.usgs.gov/publication/wsp2249
ID  - wsp2249
ER  -