Haggstrom Gus W. <br/><br/>
A Comparison of alternative methods for estimating treatment effects./ 
Gus W. Haggstrom. 
 - California:  Rand Corporation.  1973 
 - p.;  28 cm 
 - Rand Corporation papers;  P-5067 .
 - Rand Corporation papers;  P-5067 .
<br/><br/><label>ISBN: </label> Hadiah