Zenith Data Systems <br/><br/>
Microsoft MS-Dos Version 3   Primary Command Guide  

 - Primera Edición 
 - Michigan:  HEATH,  1986. 
 - Pag. 180  ilu., fig.  17x21 
 - Volume II .
<br/><br/> Part III: Primary Command Guide  
<br/><br/><br/>En eng 
<br/><br/><label>Dewey Class. No.: </label>001.642  / M 596