Dieter Pfoser Nectaria Tryfona Capturing Fuzziness and Uncertainty of Spatiotemporal Objects. 112-126 2001 conf/adbis/2001 ADBIS http://link.springer.de/link/service/series/0558/bibs/2151/21510112.htm db/conf/adbis/adbis2001.html#PfoserT01