Sommer, Robert. <br/><br/>
A practical guide to behavioral research :  tools and techniques / 
Robert Sommer and Barbara B. Sommer. 
 - New York :  Oxford University Press,  1980. 
 - viii, 256 p. :  ill. ;  24 cm. 
<br/><br/> Includes index and bibliographical references. 
<br/><br/><label>ISBN: </label>0195026918 0195026926  pbk 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Psychological research.<br/>Social sciences--Research.<br/>Behavior--Research--Methods.