On the existence of 1-factors in partial squares of graphs
On the existence of a -factor in the fourth power of a graph
On the Existence of Certain Graphs with Diameter Two
On the existence of graphs with a certain ordering of vertices
On the Extension of Graphs with a Given Diameter without Superfluous Edges
On the intersection graph of a commutative distributive groupoid
On the lattice of additive hereditary properties of finite graphs
In this paper it is proved that the lattice of additive hereditary properties of finite graphs is completely distributive and that it does not satisfy the Jordan-Dedekind condition for infinite chains.
On the line graph of the square and the square of the line graph of a connected graph
On the Non-Existence of Certain Nearly Regular Planar Maps with Two Exceptional Faces
On the number of cycles in a graph
On the number of fixed points for a continuous map of a finite connected graph.
On the p-domination number of cactus graphs
Let p be a positive integer and G = (V,E) a graph. A subset S of V is a p-dominating set if every vertex of V-S is dominated at least p times. The minimum cardinality of a p-dominating set a of G is the p-domination number γₚ(G). It is proved for a cactus graph G that γₚ(G) ⩽ (|V| + |Lₚ(G)| + c(G))/2, for every positive integer p ⩾ 2, where Lₚ(G) is the set of vertices of G of degree at most p-1 and c(G) is the number of odd cycles in G.
On the placement problem of Reeb components.
On the reconstruction of countable forests.
On the Set-Partitioning Problem
On the singular graph and the Weyr characteristic of an M-matrix.
On the size of a maximal induced tree in a random graph
On the union of matching matroids
On tree-complete graphs
On two graph-theoretical problems from the conference at Nová Ves u Branžeže