1. OMG, UML Semantics Version 1.1 (ad/97-08-04) and UML Notation Version 1.1 (ad/97-08-05), 1997.
2. ISO/IEC 19505, OMG Unified Modeling Language (UML2.1.2) – Part 1 Infrastructure and Part 2 Superstructure, 2012.
3. Research Directions in Domain Engineering,2013
4. Metamodelling for Software Engineering;Gonzalez-Perez,2008
5. Matters of (meta-) modelling;Kühne;Software and Systems Modeling,2006