Goce Trajcevski Oliviu Ghica Peter Scheuermann Roberto Tamassia Isabel F. Cruz Alternating multiple tributaries + deltas. 28-34 2008 DMSN http://doi.acm.org/10.1145/1402050.1402057 conf/dmsn/2008 db/conf/dmsn/dmsn2008.html#TrajcevskiGSTC08