1. Rook domains, Latin squares, affine planes, and error-distributing codes;Golomb;IEEE Trans. Information Theory,1964
2. Some Improved Bounds on Covering Sets;Horton,1968
3. A combinatorial problem in matching;Kalbfleisch;J. London Math. Soc.,1969
4. Some new results for the covering problem;Kalbfleisch,1969