Schrikhande, M. S.; Mavron, Vassili C.; McDonough, Thomas(2003-03)

We show that a quasi-symmetric design with intersection numbers 1 and y > 1 and a good block belongs to one of three types: (a) it has the same parameters as PG 2(4, q), the design of points and planes in projective 4-space; ...

Schrikhande, M. S.; Mavron, Vassili C.; McDonough, Thomas(2003-03)

We show that a quasi-symmetric design with intersection numbers 1 and y > 1 and a good block belongs to one of three types: (a) it has the same parameters as PG 2(4, q), the design of points and planes in projective 4-space; ...