1. Self-orthogonal latin squares;Brayton,1976
2. Latin Squares and Their Applications;Dénes,1974
3. Near-orthogonal latin squares;Heinrich;Utilitas Math.,1977
4. Sub-latin squares and incomplete orthogonal arrays;Horton;J. Combinatorial Theory Ser. A,1974
5. Construction of quasigroups using the singular direct product;Lindner,1971