TY  - RPRT
TI  - Directivity in NGA earthquake ground motions: Analysis using isochrone theory
AU  - P. Spudich
AU  - B.S.J. Chiou
PY  - 2008
DO  - 10.1193/1.2928225
UR  - https://pubs.usgs.gov/publication/70000553
ID  - 70000553
ER  -