TY  - RPRT
TI  - Census tracts, 1970, Washington urban area, D.C., MD., and VA.
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1974
DO  - 10.3133/i858c
UR  - https://pubs.usgs.gov/publication/i858C
ID  - i858C
ER  -