Ritchie, C <br/><br/>
Operating systems : incorporating UNIX and MS-DOS 

 - New Delhi  BPB Publications  1993 
 - vii, 226p.  
<br/><br/> Includes bibliographical references and index 
<br/><br/><label>Subjects--Topical Terms: </label><br/>DOS -- Operating systems<br/>Operating systems<br/>UNIX -- Operating systems