Patent-nachrichten :  patent listings in the Deutsche Uhrmacher-Zeitung 1877-1932 / 
D.K. Stevenson. 
 - 2 volumes :  illustrations ;  30 cm 
<br/><br/>Bd. 1. 1877-1909 -- Band 2. 1910-1932. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Clocks and watches--Patents--Germany--19th century.<br/>Clocks and watches--Patents--Germany--20th century.
<br/><br/><label>Subjects--Index Terms: </label>Timekeeper (general) Germany Ruhrei patent Stevenson, Douglas K. NA/Other