We consider 5-configurations defined by their incidence matrices over the field GF(2), which must be non-degenerate and contain in each row and each column has exactly 5 ones, and the inverse the matrix must also have this property. Families are given 5-configurations isomorphic to each other on sets of greater cardinality or equal to 9.

Komyagin Maxim Mikhailovich,  LLC 'Certification Research Center'

Malyshev Fedor Mikhailovich,  Mathematical Institute. V.A. Steklov RAS