Webb,Eugene,J <br/><br/>
Unobtrusive measures 

 - Chicago :  Rand macnally and company ,  1966. 
 - viii,224p.  : ill.  ; 23cm 
<br/><br/>Include bibliographical references and index 
<br/><br/><label>ISBN: </label>528-68694-1 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Social science - Research
<br/><br/><label>LC Class. No.: </label>ARC H62.W38