McMahon, Thomas. <br/><br/>
The Mass Explained / 

 - Great Wakering :  Mayhew- McCrimmon Ltd,  1977. 
 - 130 p. 
<br/><br/><label>ISBN: </label>0855972017 
<br/><br/><label>Dewey Class. No.: </label>264.36  / MCM