Science & Technilogy for civil service s examinations/ 
Singh,Ashok Kumar 
 - 1st.ed. 
 - New Delhi:  Tata Mcgrow hill pvt.ltd.,  2008. 
 - 646 
<br/><br/><label>ISBN: </label>9780070655485 
<br/><br/><label>Dewey Class. No.: </label>351076  / SIN/S