Singh, H.S. <br/><br/>
Principles of environmental conservation 
by H.S. Singh 
 - Dehradun  International Book Distributors  1989 
 - 273p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Natural resources
<br/><br/><label>Dewey Class. No.: </label>Y Si64