Heywood ,I <br/><br/>
An introduction to geographical infomation systems/ 
Ian Heywood. 
 - Singapore  Addison Wesley Longman Limited.  1998 
 - xiii,279p.  pbk. 
<br/><br/><label>ISBN: </label>0130162388 
<br/><br/><label>LC Class. No.: </label>G70.212.H4 1998