1. Fuzzy Implications, Studies in Fuzziness and Soft Computing, vol. 231;Baczyński,2008
2. Analytical Solution Methods for Fuzzy Relational Equations;De Baets,2000
3. Fuzzy closure operators;Belohlávek;J. Math. Anal. Appl.,2001
4. Computing the lattice of all fixpoints of a fuzzy closure operator;Belohlávek;IEEE Trans. Fuzzy Syst.,2010
5. Lattice Theory;Birkhoff,1967