Wolf-Tilo Balke Ulrich Güntzer Werner Kießling On Real-Time Top k Querying for Mobile Services. 125-143 2002 conf/coopis/2002 CoopIS/DOA/ODBASE http://link.springer.de/link/service/series/0558/bibs/2519/25190125.htm db/conf/coopis/coopis2002.html#BalkeGK02