Cook, Thomas D. <br/><br/>
Quasi-experimentation :  
By Thomas D Cook and Donald T Campbell. 
 - 1st ed. 
 - Boston :  Houghton mifflin Company ,  1979. 
 - xii,405p. ;  PB  23.6 cm 
<br/><br/><label>ISBN: </label>0395307902 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Validity<br/>Inferring cause from passive observation<br/>The conduct of randomized experiments
<br/><br/><label>Dewey Class. No.: </label>519.5   / COOT