TY  - RPRT
TI  - Paleobotany and palynology of the Bristol Hill Coal Member (Bond Formation) and Friendsville Coal Member (Mattoon Formation) of the Illinois Basin (Upper Pennsylvanian)
AU  - Debra A. Willard
AU  - T.L. Phillips
PY  - 1993
DO  - 10.2307/3515033
UR  - https://pubs.usgs.gov/publication/70017990
ID  - 70017990
ER  -