1. Lattice Theory;Birkhoff,1967
2. Selected Papers on Algebra and Topology by Garrett Birkhoff;Birkhoff,1987
3. Algebraic Theory of Lattice;Crawley,1973
4. Théorie algébrique des relations d'équivalence;Dubreil;J. Math.,1939
5. The logic of commuting equivalence relations;Finberg,1996