TY  - RPRT
TI  - Reports and maps of the Geological Survey released only in the open files, 1961
AU  - Betsy A. Weld
AU  - Erwin S. Asselstine
AU  - Arthur Johnson
PY  - 1962
DO  - 10.3133/cir463
UR  - https://pubs.usgs.gov/publication/cir463
ID  - cir463
ER  -