@misc{indiciaecc682b8a49e8, title = {Natural gamma aeroradioactivity map of the Frenchtown and part of the Riegelsville quadrangles, New Jersey and Pennsylvania}, author = {G. R. Boynton and D.R. Pittillo and G. L. Zandle}, year = {1966}, doi = {10.3133/gp571}, url = {https://pubs.usgs.gov/publication/gp571}, note = {Source identifier: gp571} }