References: UML Interactions

[Cen07] M.V. Cengarle. System Model for UML -- The Interactions Case. Methods for Modelling software Systems (MMOSS), Internationales Begegnungs- und Forschungszentrum fur Informatik (IBFI), Schloss Dagstuhl, Germanly, 2007.
[CK04] María Victoria Cengarle and Alexander Knapp. UML 2.0 Interactions: Semantics and Refinement. In Workshop on Critical Systems Development with UML (CSDUML'04, Proceedings), pages 85-99. Technical Report TUM-I0415, Institut für Informatik, Technische Universität München, 2004.
[HS03] Øystein Haugen and Ketil Stølen. STAIRS - Steps to Analyze Interactions with Refinement Semantics. In International Conference on the Unified Modeling Language (UML'03, Proceedings), volume 2863 of Lecture Notes in Computer Science, pages 388-402. Springer-Verlag, 2003.
[Stö03] Harald Störrle. Assert, Negate and Refinement in UML-2 Interactions. In Workshop on Critical Systems Development with UML (CSDUML'03, Proceedings), pages 79-94. Technical Report TUM-I0317, Institut für Informatik, Technische Universität München, 2003.