Special quality tubes 
Philips 
 - Eindhoven  Philips Electron Tube Division  1966 
 - 1 c.  tbl., graf., şkl.  20 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Special quality tubes.
<br/><br/><label>Dewey Class. No.: </label>621.381 SPE 1966