Sin autor <br/><br/>
IBM System/360 Operating System :  Operator's Procedures : OS Release 21 

 - 2nd ed. 
 - Nueva York :  [S.n.],  1971 
 - 46 p.  ;  30 cm. 
 - IBM systems reference library .
<br/><br/><label>Standard No.: </label>DIF-M2493 
<br/><br/><label>Subjects--Topical Terms: </label><br/>OS/360<br/>IBM SYSTEM/360