Joonhee Kwon Yong-Ik Yoon Efficient Access Technique Using Levelized Data in Web-Based GIS. 64-71 2002 conf/waim/2002 WAIM http://link.springer.de/link/service/series/0558/bibs/2419/24190064.htm db/conf/waim/waim2002.html#KwonY02