1. Orthogonal Designs: Quadratic Forms and Hadamard Matrices;Geramita,1979
2. Combinatorial Theory;Hall,1967
3. Hermann König, private communication.
4. Symmetric conference matrices of order pq2+1;Mathon;Canad. J. Math.,1978
5. On skew-Hadamard matrices;Seberry;Ars Combin.,1978