Glen, Harold T. <br/><br/>
Exploring Power Mechanics 
Harrold T. Glenn 
 - 3rd ed. 
 - Illinois  Chas A. Bennett Co.  1973 
 - 240p.:  ill.;  26cm. 
<br/><br/><label>ISBN: </label>870021192 
<br/><br/><label>Dewey Class. No.: </label>621/  / GLE