Park , K.   . <br/><br/>
Text Book of Preventive and Social Medicine /   Textual Documents 

 - 15th /   . 
 -  M/s Banarsidas Bhanot Pub.  ,   1997. 
 - 167 ;    
<br/><br/><label>ISBN: </label>  
<br/><br/><label>Subjects--Index Terms: </label>Medical Science 
<br/><br/><label>Dewey Class. No.: </label>614  / PAR