World heritage twenty years later :  based on papers presented at the World Heritage and other workshops held during the IVth World Congr ess on National Parks and Protected Areas, Caracas, Venezuela, February 1992 / 
 World heritage 20 years later 
compiled by Jim Thorsell with the editorial assistance of Ja cqueline Sawyer. 
 - Gland, Switzerland :  IUCN, the World Conservation Union, in colla boration with UNESCO's World Heritage Committee,   1992. 
 - 191 p. :  ill. ;   24 cm. 
<br/><br/><label>ISBN: </label>2831701090 (chlorinefree paper) 
<br/><br/><label>LCCN: </label>94-199064 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Natural areas-- Congresses.<br/>National parks and reserves-- Congresses.
<br/><br/><label>Dewey Class. No.: </label>333.78