Jan Chomicki Yuguo Liu Peter Z. Revesz Animating Spatiotemporal Constraint Databases. 224-241 http://link.springer.de/link/service/series/0558/bibs/1678/16780224.htm 1999 conf/stdbm/1999 Spatio-Temporal Database Management db/conf/stdbm/stdbm99.html#ChomickiLR99