Standard qualification procedure (tentative) 

 - American welding society  New York  1941 
 - 39p.  fig. 
<br/><br/><label>Nat. Bib. No.: </label>588 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Physics
<br/><br/><label>Universal Decimal Class. No.: </label>621.791  / STA