TY  - RPRT
TI  - Isotopic evidence for the source of sulfur in the Upper Freeport coal bed (west-central Pennsylvania, U.S.A.)
AU  - E.C. Spiker
AU  - B.S. Pierce
AU  - A. L. Bates
AU  - R.W. Stanton
PY  - 1994
DO  - 10.1016/0009-2541(94)90045-0
UR  - https://pubs.usgs.gov/publication/70017123
ID  - 70017123
ER  -