Francisco J. López-Pellicer Aneta J. Florczyk Javier Lacasta F. Javier Zarazaga-Soria Pedro R. Muro-Medrano Administrative Units, an Ontological Perspective. 354-363 2008 ER Workshops http://dx.doi.org/10.1007/978-3-540-87991-6_42 conf/er/2008w db/conf/er/erw2008.html#Lopez-PellicerFLZM08