Progress in Electronics Series of 1973

Front:
LEE DEFOREST 1873-1961 "FATHER OF RADIO" INVENTOR OF THE OFFICIAL FIRST DAY OF ISSUE Art Craft AUDION TUBE Progress in Electronics SERIES OF 1973 YORK JUL 10 1973 NY De Forest Audions Judson Lindsey 4314 Nelson the Peoria, Ill. 11c AIRMAIL Progress in Electronics FIRST DAY OF ISSUE

Back:
TORK JUL 12 พระ 1973 BUY U.S. SAVINGS BONDS SK YOUR POSTMASTER