Drawings of hydraulic ram 
/ German appropriate technology exchange 
. - Eschborn  : GATE, 1979
. - 42 p.  : ill.  ; 30 cm. 
 - Aus  der arbeit von GATE .
<br/><br/><label>Source: </label> Don 
<br/><br/><label>Universal Decimal Class. No.: </label>621.227.