Inge M. C. Lemmens Maurice Nijssen Sjir Nijssen A NIAM2007 Conceptual Analysis of the ISO and OMG MOF Four Layer Metadata Architectures. 613-623 2007 conf/otm/2007-w1 OTM Workshops (1) http://dx.doi.org/10.1007/978-3-540-76888-3_84 db/conf/otm/otm2007-w1.html#LemmensNN07