TY  - BOOK
AU  - Heaton, Thomas H.
ED  - Geological Survey (U.S.)
TI  - National seismic system science plan,
T2  - Geological Survey circular
U1  - 551.22 
PY  - 1989///
CY  - Washington
PB  - U.S. Dept. of the Interior, Geological Survey
KW  - Earthquake
KW  - Seismology
ER  -