1. Lattice Theory;Birkhoff,1967
2. On the Construction of Certain Steiner Systems;Coupland,1975
3. On the Foundations of Combinatorial Theory: Combinatorial Geometries;Crapo,1970
4. Designs et hyperplans;Dehon;J. Combinatorial Theory Ser. A,1977
5. Finite Geometries;Dembowski,1968