Strong motion earthquake accelerograms : digitized and plot-ted data. Volume 1 uncorrected accelerograms, Part B : acc-elerograms IB21 through IB40 / California Institute of Tech-nology. 

 - Pasadena, Calif. : Research Laboratory 
 - 198 p. 
 - [Report] ; EERL 70-21 / CALTEC, Earthquake Engineering Rese-arch Laboratory .