TY - GEN A1 - Guizzardi, Giancarlo A1 - Wagner, Gerd A1 - Almeida, João Paulo Andrade A1 - Guizzardi, Renata T1 - Towards Ontological Foundation for Conceptual Modeling: The Unified Foundationa lOntology (UFO) Story T2 - Applied Ontology Y1 - 2015 U6 - https://doi.org/10.3233/AO-150157 SN - 1570-5838 VL - 10 IS - 3-4 SP - 259 EP - 271 ER -