@InProceedings{Seemann:1999:UML98, author = "Jochen Seemann and J{\"u}rgen Wolff von Gudenberg", title = "Extension of {UML} Sequence Diagrams for Real-Time Systems", pages = "240--252", booktitle = "The Unified Modeling Language, UML'98 - Beyond the Notation. First International Workshop, Mulhouse, France, June 1998, Selected Papers", editor = "Jean B{\'e}zivin and Pierre-Alain Muller", publisher = "Springer", series = "LNCS", volume = "1618", year = "1999", }