DL/I DOS/VS secondary indexing and logical relationships :  study guide / 
IBM 
 - 2nd ed. 
 - New York :  International Business Machines,  1980 
 - 1v. (in various pagings) :  ill. ;  29 cm. 
<br/><br/> 'Independent study program' 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Data base management