Rudra P.K., <br/><br/>
Encyclopaedia of classification and communication 
by P.K. Rudra 
 - Delhi  Anmol Publications Pvt. Ltd  2011 
 - 288p. 
<br/><br/><label>ISBN: </label>978-81-261-4674-1(set) 
<br/><br/><label>Dewey Class. No.: </label>2:51k  / Q1.1