TY  - RPRT
TI  - Reports and maps of the Geological Survey released only in the open files, 1972
AU  - Betsy A. Weld
AU  - Kathleen T. Iseri
AU  - Marvin L. Millgate
PY  - 1973
DO  - 10.3133/cir668
UR  - https://pubs.usgs.gov/publication/cir668
ID  - cir668
ER  -