Gillespie, T.D. <br/><br/>
Calibration of response-type road roughness measuring syste-ms / T.D. Gillespie , M.W. Sayers , and L. Segel. 

 - Washington, D.C. : TRB 
 - 81 p. 
 - Research Program Report ; 228 / Transportation Research Boa- rd .