Dotson, K.W. <br/><br/>
Vertical and torsional impedances for radially in homogeneo-us viscoelastic soil layers / by K.W. Dotson and A.S. Velet-sos 

 - Buffalo, New York : National Center for Earthquake Engineering Research 
 - 40 p. 
 - Technical report NCEER ; 87-0024 .