Some Results on Reed’s Conjecture about omega, Delta, and chi with respect to alpha
(with A. Kohl)
Discrete Mathematics 310 (2010), 1429–1438
Structural properties and hamiltonicity of neighborhood graphs
(with M. Sonntag and H.-M. Teichert)
erscheint in Graphs and Combinatorics (2010)
2009
Rainbow Connection in Graphs with Minimum Degree Three
Lecture Notes in Computer Science 5874 (2009), 432-437
On F-independence in graphs
(with F. Göring, J. Harant and D. Rautenbach)
Discussiones Mathematicae Graph Theory 29 2 (2009), 377-383
On the circumference of a graph and its complement
(with R.J. Faudree and L. Lesniak)
Discrete Math. 309(19) (2009), 5891-5893
Colourings of graphs with two consecutive odd cycle lengths
(with S. Matos Camacho)
Discrete Math. 309(15) (2009), 4916-4919
Structural properties and hamiltonicity of neighborhood graphs
(with M. Sonntag and H.-M. Teichert)
Universität zu Lübeck, Schriftenreihe der Institute für Informatik/Mathematik, Serie A, Technical Report A-09-01 (2009), 1-28
2008
Efficiency in exponential time for domination-type problems
Discrete Applied Mathematics 156(17) (2008), 3291-3297
Non-path spectrum sets
(with G. Chen, R.J. Faudree, X. Li)
Journal of Graph Theory 58(4) (2008), 329-350
Locally Dense Independent Sets in Regular Graphs of Large Girth — An Example of a New Approach
(with F. Göring, J. Harant, D. Rautenbach)
in Research Trends in Combinatorial Optimization, Springer-Verlag Berlin Heidelberg (2008), 163-183
Algorithmic bounds for the chromatic number
Optimization: A Journal of Mathematical Programming and Operations Research 57(1) (2008), 153-158
2007
On the complexity of 4-coloring graphs without long induced paths
(with V. B. Le and B. Randerath)
Theoretical Computer Science 389 (1-2) (2007), 330-335
Chvátal Erdös condition and 2-factors with a specified number of components
(with G. T. Chen, K. Kawarabayashi and K. Ota, A. Saito)
Discussiones Mathematicae Graph Theory 27 (3) (2007), 401-408
[r,s,t]-Colourings of paths (with M. Salvador Villa)
Opuscula Math. 27 (2007), 131-149
Rainbows in the Hypercube
(with M. Axenovich, H. Harborth, A. Kemnitz, M. Möller)
Graphs and Combinatorics 23 (2007), 123-133
New sufficient conditions for hamiltonian and pancyclic graphs
(with M. Wozniak)
Discussiones Mathematicae Graph Theory 27 (1) (2007), 29-38
A new upper bound for the chromatic number of a graph
Discussiones Mathematicae Graph Theory 27 (1) (2007), 137-142
Independence number and vertex-disjoint cycles
(with Y. Egawa, H. Enomoto, S. Jendrol, K. Ota)
Discrete Mathematics 307 (11-12) (2007), 1493-1498
Degree conditions for hamiltonicity: Counting the number of missing edges
(with R.J. Faudree, R.H. Schelp, A. Saito)
Discrete Mathematics 307 (2007) 873-877
2006
On Reed's conjecture about omega,Delta and chi (with B. Randerath)
Graph Theory in Paris (Series: Trends in Mathematics),
Proceedings of a Conference in Memory of Claude Berge (2006) 339-346
A lower bound on the independence number of a graph in terms of degrees
(with J. Harant)
Discussiones Mathematicae Graph Theory 26 (3) (2006) 431-438
Upper bounds for the chromatic number of a graph
Electronic Notes in Discrete Mathematics 25 (2006) 147-148
Chvátal-Erdös condition and pancyclism
(with E. Flandrin, H. Li, A. Marczyk, M. Wozniak)
Discussiones Mathematicae Graph Theory 26 (2) (2006) 225-342
Extremal Problems for Imbalanced Edges (with D. Rautenbach)
Graphs and Combinatorics 22 (1) (2006) 103-111
2005
Exact Algorithms for Minimum Dominating Set (with B. Randerath)
Technical Report: zaik2005-501, Universität zu Köln (2005)
An asymptotic result for the path partition conjecture (with M. Frick)
Electron. J. Combin. 12 (2005), paper 48
Ramsey (K1,2,K3)-minimal graphs (with M. Borowiecki, E. Sidorowicz)
Electron. J. Combin. 12 (2005), paper 20
The Cycle-Complete Graph Ramsey Number r(C5, K7)
Discussiones Mathematicae Graph Theory 25 (1-2) (2005) 129-139
2004
3-Colorability in P for P6-free graphs (with B. Randerath)
Discrete Applied Mathematics 136 (2004) 299-313
Vertex colouring and forbidden subgraphs - a survey (with B. Randerath)
Graphs and Combinatorics 20 (2004) 1-40
Cycle lengths and chromatic number of graphs (with P. Mihók)
Discrete Mathematics 286 (2004) 147-149
Rainbow numbers for matchings and complete graphs
Discrete Mathematics 286 (2004) 157-162
2003
All cycle-complete graph Ramsey numbers r(Cm, K6)
Journal of Graph Theory 44 (2003) 251-260
Two-factors each component of which contains a specified vertex
(with Y. Egawa, H. Enomoto, R.J. Faudree, H. Li)
Journal of Graph Theory 43 (2003) 188-198
Degree conditions for k-ordered hamiltonian graphs
(with R.J. Faudree, R.J. Gould, A.V. Kostochka, L. Lesniak, A. Saito)
Journal of Graph Theory 42 (2003) 199-210
The Ramsey Number r(C_7,C_7,C_7) (with R. Faudree, A. Schelten)
Discussiones Mathematicae Graph Theory 23 (1) (2003) 141-158
0-Dual Closures for Several Classes of Graphs (with A. Ainouche)
Graphs and Combinatorics 19 (3) (2003) 297-307
2002
Independence Number and Vertex-Disjoint Cycles
(with Y. Egawa, H. Enomoto, S. Jendrol, K. Ota)
Preprint 2002
Chromatic Number of Graphs each Path of which is 3-colourable
(with B. Randerath)
Result. Math 41 (2002) 150-155
A Note on Brook's Theorem for Triangle-free Graphs (with B. Randerath)
Australasian Journal of Combinatorics 26 (2002) 3-10
Forbidden subgraphs implying the MIN-algorithm gives a maximum independent set
(with J. Harant, Z. Ryjácek)
Discrete Mathematics 256 (2002) 193-201
3-Colourability and Forbidden Subgraphs II: Polynomial Algorithms
(with B. Randerath, M. Tewes)
Discrete Mathematics 251 (2002) 137-153
Vertex-Pancyclic Graphs (with B. Randerath, M. Tewes, L. Volkmann)
Discrete Applied Mathematics 120 (2002) 219-237
Longest paths and longest cycles with large degree sums (with M. Tewes)
Graphs and Combinatorics 18 (2002) 633-643
2001
On the Independence Number of a Graph in Terms of Order and Size
(with J. Harant)
Discrete Mathematics 232, No. 1-3, (2001) 131-138
On a Max-Min Problem concerning Weights of Edges (with S. Jendrol)
Combinatorica 21 (3) (2001) 351-359
On weights of induced paths and cycles in claw-free and K_(1,r)-free graphs
(with J. Harant, M. Voigt, S. Jendrol, B. Randerath, Z. Ryjácek)
Journal of Graph Theory 36 No. 3 (2001) 131-143
Colouring Graphs with Prescribed Induced Cycle Lengths (with B. Randerath)
Discussiones Mathematicae Graph Theory 21 (2) (2001) 267-281
On the Stability for Pancyclicity
Discussiones Mathematicae Graph Theory 21 (2) (2001) 223-228
2000
Closure concepts: a survey (with H. Broersma, Z. Ryjácek)
Graphs and Combinatorics 16 (2000) 17-48
On-line rankings of graphs (with Zs. Tuza, M. Voigt)
Discrete Mathematics 212 (2000) 141-147
Claw-free and generalized bull-free graphs of large diameter are Hamiltonian
(with R.J. Faudree, Z. Ryjácek)
Tatra Mt. Math. Publ. 18 (1999) 105-113
1999
On quadrilaterals in a graph (with B. Randerath, H. Wang)
Discrete Mathematics 203 (1999) 229-237
Forbidden subgraphs, stability and Hamiltonicity
(with J. Brousek, Z. Ryjácek)
Discrete Mathematics 197 (1999) 143-155
1998
A planarity criterion for cubic bipartite graphs
(with T. Böhme, J. Harant, A. Pruchnewski)
Discrete Mathematics 191 (1998) 31-43
2-factors and Hamiltonicity (with Z. Ryjácek)
Discrete Mathematics 191 (1998) 171-177
Ramsey numbers r(K3,G) for G = K7-2P2 and G = K7-3P2 (with A. Schelten)
Discrete Mathematics 191 (1998) 191-196
Approximating Maximum Independent Set in k-Clique-Free Graphs
Lecture Notes in Computer Science 1444 (1998) 159
1997
On the computational complexity of (O,P)-partition problems
(with J. Kratochvíl)
Discussiones Mathematicae Graph Theory 17 (1997) 253-258
Small cycles in Hamiltonian graphs (with U. Schelten)
Discrete Applied Mathematics 79 (1997) 201-211
Local connectivity and cycle extension in claw-free graphs
(with R. J. Faudree, Z. Ryjácek)
Ars Combinatoria 47 (1997) 185-190
Ramsey numbers r(K3,G) for connected graphs G of order seven
(with A. Schelten)
Discrete Applied Mathematics 79 (1997) 189-200
Dirac's minimum degree condition restricted to claws
(with H. J. Broersma, Z. Ryjácek)
Discrete Mathematics 167 (1997) 155-166
1996
Fast exact colouring algorithms
Tatra Mt. Math. Publ. 9 (1996) 15-30
On generalizing a theorem of Fraisse
Ars Combinatoria 29 (1990) 49-58
Toughness and Hamiltonicity in almost claw-free graphs
(with H. Broersma, Z. Ryjácek)
Journal of Graph Theory 21 (1996) 431-439
Unifying results on Hamiltonian claw-free graphs
(with H. Broersma, Z. Ryjácek)
Tatra Mt. Math. Publ. 9 (1996) 31-39
1995
Forbidden subgraphs and cycle extendability (with R. Faudree, Z. Ryjácek)
J. Combin. Math. Combin. Comput. 19 (1995) 109-128
The flower conjecture in special classes of graphs (with Z. Ryjácek)
Discussiones Mathematicae Graph Theory 15 (2) (1995) 179-184
Problems remaining NP-complette for sparse or dense graphs
Discussiones Mathematicae Graph Theory 15 (1) (1995) 33-41
Forbidden subgraphs and pancyclicity
(with R. Faudree, R. Gould, Z. Ryjácek)
Congr. Numer. 109 (1995) 13-32
Insertible vertices, neighborhood intersections, and Hamiltonicity
(with A. Ainouche)
Journal of Graph Theory 20 (1995) 123-135
On the independence number in (K1,r+1)-free graphs (with Z. Ryjácek)
Discrete Mathematics 138 (1995) 365-374
An approximation algorithm for 3-Colourability
Lecture Notes in Computer Science 1017 (1995) 146-151
1994
On path-tough graphs (with P. Dankelmann, T. Niessen)
SIAM J. Discrete Math. 7 (1994) 571-584
A closure concept based on neighborhood unions of independent triples
(with H. Broersma)
Discrete Mathematics 124 (1994) 37-47
Subgraphs, closures and Hamiltonicity (with H. Broersma)
Discrete Applied Mathematics 51 (1994) 39-46
Reverse-Fit: A 2-optimal algorithm for packing rectangles
Lecture Notes in Computer Science 855 (1994) 290-299
Deciding 3-colourability in less than O(1.415^n) steps
Lecture Notes in Computer Science 790 (1994) 177-188
1993 und älter
Computation of the 0-dual closure for Hamiltonian graphs
Discrete Mathematics 111 (1993) 455-464
Solving 3-satisfiability in less than 1.579^n steps
Lecture Notes in Computer Science 702 (1993) 379-394
A fast sequential and parallel algorithm for the computation of the
k-closure of a graph
Lecture Notes in Computer Science 411 (1990) 211-217
A polynomial algorithm for Hamiltonian graphs based on transformations
Ars Combinatoria 25 (1988) 55-74