Markus Franke Andreas Kamper Anke Eßer Pricing Energy in a Multi-Utility Market. 433-440 2006 GfKl http://dx.doi.org/10.1007/978-3-540-70981-7_49 conf/gfkl/2006 db/conf/gfkl/gfkl2006.html#FrankeKE06