Elektrische Uhren : deutsche reichs Patente, 1877-1941.

Elektrische Uhren : deutsche reichs Patente, 1877-1941. - 1 volume (various pagings) ; 30 cm


Clocks and watches, Electric--Germany--1877-1941.--Patents

electrical electromechanical patent reischspatent Patent Timekeeper (general) Germany Reference Government


Patents.