@misc{indiciaec6801cbd264c,
  title = {Aeromagnetic map of part of the Alburtis quadrangle, Lehigh, Berks, and Northampton Counties, Pennsylvania},
  author = {Randolph Wilson Bromery and G. L. Zandle and and others},
  year = {1961},
  doi = {10.3133/gp266},
  url = {https://pubs.usgs.gov/publication/gp266},
  note = {Source identifier: gp266}
}