Water : 
a precious resource / 
 - United States :  National Geographic Society (U.S.)  1980. 
 - 1 videocassette of 1 (ca. 23 min.) :  sd., col. ;  1/2 in. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Conservation of natural resources<br/>Hydrology<br/>Water
<br/><br/><label>Index Terms--Genre/Form: </label><br/>Educational.
<br/><br/><label>LC Class. No.: </label>TD390.W38 1980