P. H. Fisher, Tim Penttila, Gordon F. Royle. Symmetric designs, polarities and sub-designs. Discrete Mathematics, 71(1):19-32, 1988. [doi]
@article{FisherPR88, title = {Symmetric designs, polarities and sub-designs}, author = {P. H. Fisher and Tim Penttila and Gordon F. Royle}, year = {1988}, doi = {10.1016/0012-365X(88)90027-1}, url = {http://dx.doi.org/10.1016/0012-365X(88)90027-1}, researchr = {https://researchr.org/publication/FisherPR88}, cites = {0}, citedby = {0}, journal = {Discrete Mathematics}, volume = {71}, number = {1}, pages = {19-32}, }