An efficient implementation of certain iterative refinement preconditioners
S. Petrova, Computing 52 (1994) 51–63.

Preconditioning elliptic problems on grids with multilevel local refinement
P.S. Vassilevski, S. Petrova, R.D. Lazarov, Mathematica Balkanica 8 (1994) 179–196.

Computing extreme eigenvalues of large sparse symmetric problems
C. Brand, S. Petrova, in: I.T. Dimov, B. Sendov, P.S. Vassilevski,  e World Scientific Pub Co Inc (Eds.), Advances in Numerical Methods and Applications: Proceedings of the Third International Conference, 1994.

On-the-Job Training, innerbetriebliche Karrierepfade und Einkommensentwicklung / On-the-Job Training, Promotion and Earnings Dynamics Observed Within Firms
F. Büchel, M. Pannenberg, Jahrbücher Für Nationalökonomie Und Statistik 213 (1994).

Directional K- Functionals
C. Cottin, Results in Mathematics 24 (1993) 211–221.

Directional extensions of univariate operators and Boolean sum approximation
C. Cottin, Analysis 13 (1993) 185–200.

Simultaneous approximation and global smoothness preservation
C. Cottin, H.H. Gonska, in: Circolo Matematico di Palermo (Ed.), Proceedings of the Second International Conference in Functional Analysis and Approximation Theory, 1993.

Korovkin-type theorems for generalized Boolean sum operators
C. Badea, C. Cottin, in: Societatis Janos Bolyai  (Ed.), Proc. Conf. “Approximation Theory” Kecskemét 1990, Colloquia Mathematica Societatis Janos Bolyai 58, 1992, pp. 51–68.

A Jackson-type theorem on approximation by bounded trigonometric blending polynomials
C. Cottin, in: K.G. Ivanov, P.P. Petrushev, B.H. Sendov, V.A. Popov, Publ. House of the Bulgarian Academy of Sciences (Eds.), Constructive Theory of Functions, Proc. Conf. Varna 1991, Sofia, 1992, pp. 77–83.

A note on global smoothness preservation by Boolean sum operators
C. Cottin, H.H. Gonska, in: K.G. Ivanov, P.P. Petrushev, B.H. Sendov, V.A. Popov, Publ. House of the Bulgarian Academy of Sciences (Eds.), Constructive Theory of Functions, Proc. Conf. Varna 1991, Sofia, 1992, pp. 85–91.

Hierarchien: Status und Entlohnung/On the Pareto-Efficiency of Profit-Sharing-Contracts
V. Carstensen, Jahrbücher Für Nationalökonomie Und Statistik 210 (1992) 445–456.

Finite Difference Schemes on Triangular Cell-Centered Grids with Local Refinement
P.S. Vassilevski, S. Petrova, R.D. Lazarov, SIAM Journal on Scientific and Statistical Computing 13 (1992) 1287–1313.

‘Neue Selbständige’ in Ostdeutschland. Statusentscheidung, Realisierungschancen und materielle Zufriedenheit
M. Pannenberg, F. Büchel, Mitteilungen Aus Der Arbeitsmarkt- Und Berufsforschung 25 (1992) 544–552.

Erwerbsbiographische Folgerisiken von Kurzarbeit und Arbeitslosigkeit. Eine empirische Analyse für Ostdeutschland
M. Pannenberg, F. Büchel, Mitteilungen Aus Der Arbeitsmarkt- Und Berufsforschung 25 (1992) 158–167.

Approximation by bounded pseudo-polynomials
C. Cottin, in: Function Spaces, Proc. Conf. Poznan 1989, Teubner, 1991, pp. 152–161.

Global smoothness preservation by multivariate approximation operators
C. Anastassiou, C. Cottin, H. Gonska, in: S. Baron, D. Leviatan (Eds.), Israel Mathematical Conference Proceedings, Vol. IV, 1991, pp. 31–44.

Global smoothness of approximating functions
G.A. Anastassiou, C. Cottin, H.H. Gonska, Analysis 11 (1991).

3D reconstruction of closed objects by piecewise cubic Bézier patches
C. Cottin, R. van Damme, in: D.C. Handscomb (Ed.), The Mathematics of Surfaces III, Proc. Conf. Bath 1990, Oxford University Press, 1990.

Mixed K-functionals: A measure of smoothness for blending-type approximation
C. Cottin, Mathematische Zeitschrift 204 (1990) 69–83.

Inverse theorems for blending-type approximation
C. Cottin, in: C.K. Chui, L.L. Schumaker, J.D. Ward (Eds.), Approximation Theory VI, Proc. Conf. College Station (Texas), Academic Press, 1989, pp. 149–152.