Adhikary, Shankar N. <br/><br/>
A Text book on computer science: class xi (second edition) 

 - Kathmandu  Buddha Academic Publishers and Distribution  2008 
 - p. 224 , ill. 
<br/><br/><label>Subjects--Index Terms: </label>Science;Eletronic data processing;computer software;computer system 
<br/><br/><label>Dewey Class. No.: </label>004