Strong motion earthquake accelerograms : digitized and plot-ted data. Vol. 1 uncorrected accelerograms, Part A : accele-rograms IA1 through IA20 / California Institute of Technolo-gy. 

 - Pasadena, Calif. : Research Laboratory 
 - [39] p. 
 - [Report] ; EERL 70-20 / CALTEC, Earthquake Engineering Rese-arch Laboratory .