Spencer scientific instruments 

 - Buffalo, New York  American Optical Company  1946 
 - 207 p.  ilus., láms. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>INSTRUMENTOS OPTICOS<br/>MICROSCOPIOS
<br/><br/><label>Universal Decimal Class. No.: </label>A/681.4/A49