Index to enviromental studies / 
National Information Center for Educational Media. 
 - Los Angeles :  National Information Center for Educational Media,  1977 
 - 1113 p. ;  28 cm. 
<br/><br/><label>ISBN: </label>0893200123 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology--Audio--visual aids--Indexes.<br/>Environmental protection--Audio--visual aids--Indexes.<br/>Science--Audio--visual aids--Indexes.