References
- Barbut, M., and B. Monjardet. 1970. Ordre et classification. Algèbre et Combinatoire. Vol. II, Hachette.
- Birkhoff, G. 1940. Lattice Theory. 1st ed. Providence, RI: American Mathematical Society.
- Ganter, B., and R. Wille. 1999. Formal Concept Analysis, Springer-Verlag.