Johnson, R.A  &  Wichern, D.W <br/><br/>
Applied Multivariate Statistical Ananlysis 

 - 2nd ed. 
 -  New Jersey : Prentice Hall  1988 
 - 607 p. 
<br/><br/><label>ISBN: </label>0000130411469 
<br/><br/><label>Dewey Class. No.: </label>519.53  / J53