Boris Konev Carsten Lutz Dirk Walther Frank Wolter Formal Properties of Modularisation. 25-66 2009 Modular Ontologies http://dx.doi.org/10.1007/978-3-642-01907-4_3 series/lncs/5445 db/series/lncs/lncs5445.html#KonevLWW09