Sethi, Manmohan Singh <br/><br/>
Understanding our environment 
Manmohan Singh Sethi and Inderjeet Kaur Sethi 
 - New Delhi  Commonwealth Publishers  1992 
 - xv, 440p.: ill.; 22cm. 
<br/><br/><label>ISBN: </label>8111691129 
<br/><br/><label>Dewey Class. No.: </label>333.7  / SET