Cristiane A. Yaguinuma, Marilde T. P. Santos, Heloisa A. Camargo, M. C. Nicolett, and Tatiane M. Nogueira, “A Meta-Ontology for Modeling Fuzzy Ontologies and its Use in Classification Tasks based on Fuzzy Rules”, ijcisim, vol. 6, p. 13, Jan. 2014.