Börje Karlsson Simone Diniz Junqueira Barbosa Antonio L. Furtado Marco A. Casanova A Plot-Manipulation Algebra to Support Digital Storytelling. 132-144 2009 ICEC http://dx.doi.org/10.1007/978-3-642-04052-8_12 conf/iwec/2009 db/conf/iwec/icec2009.html#KarlssonBFC09