TY  - RPRT
TI  - A description of colored gravity and terrain maps for the United States and adjacent Canada east of 104 degrees
AU  - R.W. Simpson
AU  - T.G. Hildenbrand
AU  - R. H. Godson
AU  - M. F. Kane
PY  - 1982
DO  - 10.3133/ofr82877
UR  - https://pubs.usgs.gov/publication/ofr82877
ID  - ofr82877
ER  -