1. Object Management Group: OMG Unified Modeling Language (OMG UML), Superstructure—Version 2.3. Technical Report Document Number formal/2010-05-05, OMG. http://www.omg.org/spec/UML/2.3/Superstructure/PDF/ (2010). Retrieved 2011-01-18
2. Booch, G., Maksimchuk, R.A., Engle, M.W., Young, B.J., Connallen, J., Houston, K.A.: Object-oriented analysis and design with applications, 3rd edition. ACM SIGSOFT Software Engineering Notes, vol. 33 (2008)
3. Rumbaugh J.E., Blaha M.R., Premerlani W.J., Eddy F., Lorensen W.E.: Object-Oriented Modeling and Design. Prentice-Hall, New Jersey (1991)
4. Jacobson I.: Object-Oriented Software Engineering: A Use Case Driven Approach. Addison-Wesley Longman Publishing Co. Inc., Redwood City (2004)
5. Harel D.: Statecharts: a visual formalism for complex systems. Sci. Comput. Progr. 8, 231–274 (1987)