Beecher, Keith2018-06-052018-06-051956-06-11http://hdl.handle.net/2152.3/9112Correspondence from Keith Beecher to William Thornton regarding requested documents for patent.Dr. William ThorntonKeith BeecherresearchCorrespondenceROFEIRadar Optic Firing Error IndicatorDel Mar Engineering LabspatentsletterBeecher-Thornton_6-11-1956