TY  - RPRT
TI  - Quality of surface waters of the United States, 1966, Parts 5 and 6, Hudson Bay and upper Mississippi River basins, and Missouri River basin
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1971
DO  - 10.3133/wsp1993
UR  - https://pubs.usgs.gov/publication/wsp1993
ID  - wsp1993
ER  -