TY  - RPRT
TI  - Water quality of hydrologic bench marks; an indicator of water quality in the natural environment
AU  - James E. Biesecker
AU  - Donald K. Leifeste
PY  - 1974
DO  - 10.3133/cir460e
UR  - https://pubs.usgs.gov/publication/cir460E
ID  - cir460E
ER  -