TY  - RPRT
TI  - Preliminary seismotectonic map of the central Mississippi Valley and environs
AU  - A. V. Heyl
AU  - F. A. McKeown
PY  - 1978
DO  - 10.3133/mf1011
UR  - https://pubs.usgs.gov/publication/mf1011
ID  - mf1011
ER  -