1. Abel, R.J.R., Bennett F.E., Zhang H., Zhu L. A few more incomplete self-orthogonal Latin squares and related designs. Australasian J. Combinatorics, 21: 85–94 (2000)
2. Belyavskaya, G.B. r-orthogonal quasigroups I. Math Issled., 39: 32–39 (1976)
3. Belyavskaya, G.B. r-Orthogonal quasigroups II. Math Issled., 43: 39–49 (1977)
4. Belyavskaya, G.B. r-orthogonal Latin squares. In: Latin Squares: New Developments (Dénes J. and Keedwell A.D.), Elsevier, North-Holland, Amsterdam, 169–202 (Chapter 6), 1992
5. Brayton, R.K., Coppersmith D., Hoffmam A.J. Self-orthogonal latin squares. Teorie Combinatorie, Proc. Rome Conf. (Rome, 1976), Vol. I, pp. 509–517 (1976)