1. G. Birkhoff, Lattice theory, Amer. Math. Soc. Colloq. Publ. 25, 1940.
2. P. Eklund, W. Gähler, Completions and compactifications by means of monads, in: Fuzzy Logic, State of Art, Kluwer (1993) 39–56
3. W. Gähler, Monadic topology - a new concept of generalized topology, in: Recent Developments of General Topology and its Applications, Akademie Verlag 1992, 136–149.
4. W. Gähler, The general fuzzy filter approach to fuzzy topology, I, Fuzzy Sets and Systems 76 (1995) 205–224.
5. W. Gähler, The general fuzzy filter approach to fuzzy topology, II, Fuzzy Sets and Systems 76 (1995) 225–246.