Roland Billen Papers on DiSC'04 A Model for Ternary Projective Relations between Regions Publications Note: Links lead to the DBLP on the Web. Roland Billen Roland Billen, Eliseo Clementini : A Model for Ternary Projective Relations between Regions. EDBT 2004 : 310-328 1 [ 1 ] ©2005 Association for Computing Machinery