@misc{indiciae2f48cbd92c51, title = {Aeromagnetic map of part of the Newburyport West quadrangle, Essex County, Massachusetts, and Rockingham County, New Hampshire}, author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey}, year = {1970}, doi = {10.3133/gp714}, url = {https://pubs.usgs.gov/publication/gp714}, note = {Source identifier: gp714} }