Singh, Ashok  Kumar <br/><br/>
Science and technology: for civil services examinations 

 - New Delhi  Tata McGraw Hill Publishing Company  2008 
 - viii, 646 p. 
<br/><br/><label>ISBN: </label>978 0 07 065548 5 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science & technology