1. Berge, C.: Hypergraphs. Combinatorics of finite sets, Transl. from the French. North-Holland, Amsterdam (1989)
2. Birkhoff, G.: Lattice Theory. American Mathematical Society, Providence (1967)
3. Buekenhout, F.: Espaces à fermeture. Bull. Soc. Math. Belg. 19, 147–178 (1967)
4. Caspard, N., Monjardet, B.: Some lattices of closure systems on a finite set. Discrete Math. Theor. Comput. Sci. 6(2), 163–190 (electronic) (2004)
5. Cosyn, E., Uzun, H.B.: Note on two necessary and sufficient axioms for a well-graded knowledge space. J. Math. Psych. 53, 40–42 (2009)