... Constructing fuzzy ontologies based on formal concept analysis theory (Quan et al., 2006a(Quan et al., , 2006bChen et al., 2009;De Maio et al., 2009;Cross & Kandasamy, 2011) Constructing fuzzy ontologies from fuzzy database models (Blanco et al., 2005(Blanco et al., , 2008Ma et al., , 2010Ma et al., , 2011aMa et al., , 2011bZhang et al., 2008aZhang et al., , 2008bZhang et al., , 2011bZhang et al., , 2013aZhang et al., , 2013bZhang et al., , 2015) Constructing fuzzy ontologies from other data sources such as fuzzy narrower terms, fuzzy relations, among others (Widyantoro & Yen, 2001a, 2001bNikravesh et al., 2004;Angryk et al., 2006;Ceravolo et al., 2006;Nováček & Smrž, 2006;Ling et al., 2007;Tafazzoli & Sadjadi, 2008;Ghorbel et al., 2010;Inyaem et al., 2010;Alexopoulos et al., 2012) Querying over lightweight fuzzy DL ontologies (Straccia, 2006c;Pan et al., 2007Pan et al., , 2008 Querying over expressive fuzzy DL ontologies (Mailis et al., 2007;Cheng et al., 2008bCheng et al., , 2009aCheng et al., , 2009b Querying over fuzzy ontologies based on fuzzy relational databases (Buche et al., 2005;Bahri et al., 2009) Other fuzzy ontology query approaches (Widyantoro & Yen, 2001a, 2001bBulskov et al., 2002;Bandini et al., 2006;Knappe et al., 2007;Carlsson et al., 2010) Storing fuzzy ontologies (Barranco et al., 2007;Lv et al., 2009;Zhang et al., 2011a) ...