Non-orientable biembeddings of Steiner triple systems of order 15.
On 2-ranks of Steiner triple systems.
On nondistributive Steiner quasigroups
A well known result of R. Dedekind states that a lattice is nonmodular if and only if it has a sublattice isomorphic to . Similarly a lattice is nondistributive if and only if it has a sublattice isomorphic to or (see [11]). Recently a few results in this spirit were obtained involving the number of polynomials of an algebra (see e.g. [1], [3], [5], [6]). In this paper we prove that a nondistributive Steiner quasigroup (G,·) has at least 21 essentially ternary polynomials (which improves the...
On subdirectly irreducible Steiner loops of cardinality .
On the chromatic number of simple triangle-free triple systems.
On the failing cases of the Johnson bound for error-correcting codes.
On the resolvability of Hall triple systems
È ben noto che fra le classi di sistemi ternari di Hall (HTS), gli HTS Abeliani ammettano una risoluzione siccome sono esattamente gli spazi affini finiti d'ordine 3; per questi sistemi una tal risoluzione è fornita dalla relazione di parallelismo. In questa nota viene dimostrato che certe classi di HTS non Abeliani costrutti dai gruppi di Burnside , anche ammettono una risoluzione. Allora, questi esempi di HTS si possono considerare anche come spazi finiti di Sperner e dunque la nota conclude...
Orientable self-embeddings of Steiner triple systems of order 15.
Orthogonal Steiner Systems.
Partial parallel classes in Steiner systems
Poznámka o cyklických Steinerových systémoch trojíc
Properties of the Steiner triple systems of order 19.
Resolving triple systems into regular configurations.
Restricted and quasi-toral restricted Lie-Rinehart algebras
In this paper, we introduce the definition of restrictable Lie-Rinehart algebras, the concept of restrictability is by far more tractable than that of a restricted Lie-Rinehart algebra. Moreover, we obtain some properties of p-mappings and restrictable Lie-Rinehart algebras. Finally, we give some sufficient conditions for the commutativity of quasi-toral restricted Lie-Rinehart algebras and study how a quasi-toral restricted Lie-Rinehart algebra with zero center and of minimal dimension should be....
Small group divisible Steiner quadruple systems.
Some remarks on the number of different triple systems of Steiner
Steiner Systems which Admit Block Transitive Automorphism Groups of Small Rank.
Steiner triple systems and existentially closed graphs.
Steiner triple systems intersecting in pairwise disjoint blocks.
Symmetric bowtie decompositions of the complete graph.