TY - RPRT TI - Aeromagnetic map of the Lowell quadrangle, Middlesex and Essex Counties, Massachusetts, and Hillsborough County, New Hampshire AU - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey PY - 1971 DO - 10.3133/gp734 UR - https://pubs.usgs.gov/publication/gp734 ID - gp734 ER -