B. Schandl, K. Klamroth and M. M. Wiecek, "Using block norms in bicriteria optimization" in Research and Practice in Multiple Criteria Decision Making, Haimes, Y.Y. and Steuer, R.E., Eds. Springer-Verlag, 2000, pp. 149-160.

M. Ehrgott, H. W. Hamacher, K. Klamroth, S. Nickel, A. Schöbel and M. M. Wiecek, "A note on the equivalence of balance points and Pareto solutions in multiple objective programming", Journal of Optimization Theory and Applications, vol. 92, pp. 209-212, 1997.

M. Ehrgott and K. Klamroth, "Connectedness of efficient solutions in multiple criteria combinatorial optimization", European Journal of Operational Research, vol. 97, pp. 159-166, 1997.

M. Ehrgott and K. Klamroth, "Nonconnected efficiency graphs in multiple criteria combinatorial optimization" in Advances in Multiple Objective and Goal Programming, Caballero, R. and Ruiz, F. and Steuer, R.E., Eds. 1997, pp. 140-150.

K. Klamroth and I. Mengersen, "The Ramsey number r(K_1,3,C_4,K_4)", Utilitas Mathematica, vol. 52, pp. 65-81, 1997.

EWGLA 8 Proceedings: Special Issue of Studies in Locational Analysis.

K. Klamroth and I. Mengersen, "Ramsey numbers of K_3 versus (p,q)-graphs", Ars Combinatoria, vol. 43, pp. 107-120, 1996.

J. Arste, K. Klamroth and I. Mengersen, "Three color Ramsey numbers for small graphs", Utilitas Mathematica, vol. 49, pp. 85--96, 1996.

M. Heilmann, "Explicit Voronovskaja-type results for linear combinations of BDT-operators", Approximation Theory and its Applications, vol. 11, no. 1, pp. 54-61, 1995.

M. Heilmann, "Saturation of linear combinations of Baskakov-Durrmeyer-type operators", Applicable Analysis, vol. 59, no. 1-4, pp. 93-107, 1995.

K. Klamroth, "Ramsey-Zahlen für Mengen von Graphen", Technical University of Braunschweig, 1994.

M. Heilmann, "Erhöhung der Konvergenzgeschwindigkeit bei der Approximation von Funktionen mit Hilfe von Linearkombinationen spezieller positiver linearer Operatoren", Universität Dortmund, 1992.

M. Heilmann, "Rate of approximation of weighted derivatives by linear combinations of SMD-operators" in Numerical Methods in Approximation Theory - Proceedings of the conference held in Oberwolfach Germany, November 24-30, 1991, D. Braess et al., Eds. Birkhäuser, Basel, Int. Ser. Numer. Math. 105, 1992, pp. 97-115.

M. Heilmann and M. Müller,Equivalence of a weighted modulus of smoothness and a modified weighted K-functional. .... Academic Press, 1991.

M. Heilmann and M. Müller, "Direct and converse results on simultaneous approximation by the method of Bernstein-Durrmeyer operators" in Algorithms for approximation II, Proc. 2nd Int. Conf., Shrivenham/UK 1988, 1990, pp. 107-116.

M. Heilmann, "Direct and converse results for operators of Baskakov-Durrmeyer type", Approximation Theory Appl., vol. 5, no. 1, pp. 105-127, 1989.

M. Heilmann and M. Müller, "Direct and converse results on weighted simultaneous approximation by the method of operators of Baskakov-Durrmeyer type", Results in Mathematics, vol. 16, no. 3-4, pp. 228-242, 1989.

M. Heilmann, "On simultaneous approximation by optimal algebraic polynomials", Results in Mathematics, vol. 16, no. 1-2, pp. 77-81, 1989.

M. Heilmann and M. Müller, "On simultaneous approximation by the method of Baskakov-Durrmeyer operators", Numerical Functional Analysis and Optimization, vol. 10, no. 1-2, pp. 127-138, 1989.

M. Heilmann and M. Müller, "Weighted simultaneous L_p-approximation by the method of Baskakov-Durrmeyer operators" in Approximation Theory VI, Proc. 6th Int. Symp., College Station/TX USA1989, 1989, pp. 331-332.

M. Heilmann, "Commutativity of operators from Baskakov-Durrmeyer type" in Constructive Theory of Functions - Proceedings of the International Conference, Varna, Bulgaria, 1987, 1988, pp. 197-206.

M. Heilmann, "Approximation auf [0, ∞) durch das Verfahren der Operatoren vom Baskakov-Durrmeyer Typ", Universität Dortmund, 1987.