TY  - RPRT
TI  - Geologic map of the Hellertown Quadrangle, Northampton, Bucks, and Lehigh counties, Pennsylvania
AU  - Avery A. Drake
PY  - 1996
DO  - 10.3133/ofr96547
UR  - https://pubs.usgs.gov/publication/ofr96547
ID  - ofr96547
ER  -