Sommer, Robert. <br/><br/>
A practical guide to behavioral research :  tools and techniques / 
by Robert Sommer. 
 - 4th ed. 
 - New York :  OUP,  c1997. 
 - 376  p. 
<br/><br/>Includes index. 
<br/><br/><label>ISBN: </label>0195104196 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Social sciences --Research.
<br/><br/><label>LC Class. No.: </label>H 62  / .S724