Michael Leuschel Heike Wehrheim Integrated Formal Methods, 7th International Conference, IFM 2009, Düsseldorf, Germany, February 16-19, 2009. Proceedings 5423 2009 http://dx.doi.org/10.1007/978-3-642-00255-7 978-3-642-00254-0 IFM Lecture Notes in Computer Science Springer db/conf/ifm/ifm2009.html