Henry Sonnet Tobias Isenberg Jana Dittmann Thomas Strothotte Illustration Watermarks for Vector Graphics. 73-82 2003 conf/pg/2003 Pacific Conference on Computer Graphics and Applications http://doi.ieeecomputersociety.org/10.1109/PCCGA.2003.1238249 db/conf/pg/pg2003.html#SonnetIDS03