TY  - RPRT
TI  - Aeromagnetic map of parts of the Gloucester and Rockport quadrangles, Essex County, Massachusetts
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1970
DO  - 10.3133/gp724
UR  - https://pubs.usgs.gov/publication/gp724
ID  - gp724
ER  -