Concepts in environment / 
P. R. Trivedi and Gurdeep Raj 
 - New Delhi :   Akashdeep Pub. House,  c1992 [reprinted 1997] 
 - 199 p. :    ill. ;  22 cm. 
<br/><br/><label>ISBN: </label>8171582303 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Environmental sciences
<br/><br/><label>Dewey Class. No.: </label>333.7  / Con 1997