Blum ,   Milton L. Foos ,  Paul W. <br/><br/>
Data gathering: experimental methods plus 

 - New York  Harper Collins  1985 
 - 324 p.  26  cm.  PB 
<br/><br/><label>Subjects--Uniform Titles: </label><br/>Research methods
<br/><br/><label>Dewey Class. No.: </label>300.72  / BLU