http://eddiesekiguchi.blogspot.com/
geophones for shear wave velocity site analysis
https://www.google.com.gt/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=geophones+for+shear+wave+velocity+site+analysis
https://www.youtube.com/watch?v=dR0jz8HsTz8
