Flake, Stephan, and Wolfgang Müller. “Specification of Real-Time Properties for UML Models.”https://doi.org/10.1109/HICSS.2002.994469__In Proceedings of HICSS-35. Big Island, HI, USA , 2002.https://doi.org/10.1109/HICSS.2002.994469 .

Geiger, Christian, Wolfgang Müller, and W. Rosenbach. “SAM - An Animated 3D Programming Language.”https://doi.org/10.1109/VL.1998.706167__In Proceedings of the IEEE Symposium on Visual Languages. Halifax, Canada, 1998.https://doi.org/10.1109/VL.1998.706167 .