Graf, Johannes, <br/><br/>
Moderne Zeiten :  Zeitmessung auf dem Weg in die Gegenwart / 
Johannes Graf. 
 - 39 pages :  illustrations ;  21 cm 
<br/><br/><label>ISBN: </label>9783922673170 3922673171 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Time measurements--History.<br/>Clocks and watches--History.
<br/><br/><label>Subjects--Index Terms: </label>History Germany Master slave timezones atomic quartz 20th century modern Catalog electrical electronic Timekeeper (general)