Sets in the plane with many concyclic subsets.
Simple minimum coverings of Kn with copies of K4 - e.
Skeletons in multigraphs
Under a multigraph it is meant in this paper a general incidence structure with finitely many points and blocks such that there are at least two blocks through any point and also at least two points on any block. Using submultigraphs with saturated points there are defined generating point sets, point bases and point skeletons. The main result is that the complement to any basis (skeleton) is a skeleton (basis).
Small forbidden configurations. II.
Solution of Moufang problems.
Some remarks on the Steiner triple systems associated with Steiner quadruple systems
Some results on odd astral configurations.
Some results on the problem of Erdös and Hajnal.
Sublattices of certain Coxeter lattices
In this paper, we describe the sublattices of some lattices, extending previous results of [Ber]. Our description makes intensive use of graphs.
Symmetric balanced ternary designs with ...1 = 1 or 2.
Symmetric balanced ternary designs with ...1 = 1 or 2. (Summary).
Symmetric translation nets.
Symmetries in Steinhaus triangles and in generalized Pascal triangles.