Campbell, H.C <br/><br/>
Developing public library systems and services :  A guide to the organization of national and regional public library systems as a part of overall national information service planning / 
by H.C. Campbell. 
 - Paris :  UNESCO,  1982. 
 - 186 p. 
 - Documentation, libraries and archives: studies and research; 11 .
<br/><br/><label>ISBN: </label>9231019953 
<br/><br/><label>No. de Clasificación Universal Decimal: </label>027.4 =20 "1982" CAM No.11.