Encyclopaedia Britannica: A new survey of universal knowledge, Vol.21: Sordello to Textile printing 

 - Chicago  Encyclopaedia Britannica, Inc  1947 
 - 1006 
<br/><br/><label>Subjects--Topical Terms: </label><br/>General encyclopedic works
<br/><br/><label>Dewey Class. No.: </label>R 030  ENC.21