Betterley, Melvin L. <br/><br/>
Sheet metal drafting / 
Melvin L. Betterley 
 - New York  McGraw-Hill  1961 
 - 314p.  ill.  25cm. 
<br/><br/><label>ISBN: </label>0070051267  RM303.98 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mechanical drawing<br/>Sheet-metal work