Retherford, Robert D. <br/><br/>
Statistical models for causal analysis/ 
Robert D. Retherford, Minja Kim Choe. 
 - New York:  John Wiley & Sons,  1993. 
 - 258 p.:   ill.;   24 cm. 
<br/><br/>p. 251-253. 
<br/><br/><label>ISBN: </label>0471558028 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Multivariate analysis.