Gies, Frances. <br/><br/>
Cathedral, forge, and waterwheel :  technology and invention in the Middle Ages / 
Frances & Joseph Gies. 
 - New York :  HarperCollins Publishers,  c1994. 
 - 357 p.   ill. ; 
<br/><br/>Includes bibliographical references (p. [329]-343) and index. 
<br/><br/><label>ISBN: </label>9780060165901  Ksh.2500/= 
<br/><br/><label>LCCN: </label>93014293  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Technology--History.<br/>Inventions--History.<br/>Science, Medieval.
<br/><br/><label>LC Class. No.: </label>T 17 .G5