
Finitecodimensional compressions of symmetric and selfadjoint linear relations in Krein spaces. (with Tomas Azizov and Aad Dijksma)
Integral Equations and Operator Theory
86 (2016) no. 1, 7195. doi:10.1007/s0002001623132.

Partially fundamentally reducible operators in Krein spaces. (with Vladimir Derkach)
Integral Equations and Operator Theory
82 (2015) no. 4, 469518. doi:10.1007/s0002001422043.

Somewhat stochastic matrices. (with Robert I. Jewett)
The American Mathematical Monthly 122 (2015) no. 1, 3642.
doi:10.4169/amer.math.monthly.122.01.36.

On two common sequences that converge to $e$. The College Mathematics Journal 45 (2014) no. 5, 391392.
doi:10.4169/college.math.j.45.5.387.

Outer median triangles. (with Árpád Bényi). Mathematics Magazine 87 (2014) no. 3, 185195. doi:10.4169/math.mag.87.3.185.

Ceva's triangle inequalities. (with Árpád Bényi). Mathematical Inequalities & Applications 17 (2014) no. 2, 591–609.

Problem 11749. The $p$norm on ${\mathbb C}^n$ is a convex function of $p$. The American Mathematical Monthly 121 (2014) no. 1, 83.

A proof of the main theorem on Bezoutians. (with Aad Dijksma).
Elemente der Mathematik 69 (2014) no. 1, 3339. doi:10.4171/EM/243.

The Riesz basis property of an indefinite SturmLiouville problem with nonseparated boundary conditions. (with Andreas Fleige and Aleksey Kostenko). Integral Equations and Operator Theory
77 (2013) no. 4, 533557. doi:10.1007/s000200132093x.

A generalization of Routh's triangle theorem. (with Árpád Bényi).
The American Mathematical Monthly 120 (2013) no. 9, 841846. doi:10.4169/amer.math.monthly.120.09.841.
The animation that is cited in this paper can be found here.

Triangles and groups via cevians. (with Árpád Bényi). Journal of Geometry 103 (2012) no. 3, 375408.
Here you can find more information about this paper including an animation which inspired the paper.

On the reproducing kernel of a Pontryagin space of vector valued polynomials. (with Aad Dijksma)
Linear Algebra and its Applications
436 (2012), no. 5, 13121343.

Stability of roots of polynomials under linear combinations of derivatives. (with Vania Mascioni).
Constructive Approximation 32 (2010) no. 3, 523541.

Riesz basis of root vectors of indefinite SturmLiouville problems
with eigenparameter dependent boundary conditions, II. (with Paul
Binding). Integral Equations and Operator Theory 63 (2009) no. 4, 473499.
Detailed calculations for the opening example in this paper can be found
here.

On a convex operator for finite sets. (with Krzysztof Kołodziejczyk).
Discrete Applied Mathematics 155 (2007) no. 13,
17741792.
Paper's abstract and a motivating image can be found
here.

Root preserving transformations of polynomials. (with Vania Mascioni) Mathematics Magazine 80 (2007) no. 2, 136138.

Perturbations of roots under linear transformations of polynomials.
(with Vania Mascioni) Constructive Approximation 25 (2007) no. 3, 255277.

An unexpected limit of expected values. (with Robert I. Jewett)
Expositiones Mathematicae 25 (2007) no. 1, 120.

An exceptional exponential function. The College Mathematics Journal 37 (2006) no. 5, 344354.

Riesz basis of root vectors of indefinite SturmLiouville problems
with eigenparameter dependent boundary conditions, I. (with Paul
Binding) in Operator Theory and Indefinite Inner Product Spaces, The
Proceedings of the Colloquium held on the occasion of the retirement
of Heinz Langer, Vienna, Austria. 7596, Operator Theory: Advances
and Applications, Vol. 163, Birkhäuser, 2006.

Roots and polynomials as homeomorphic spaces. (with Vania Mascioni)
Expositiones Mathematicae 24 (2006) no. 1, 8195.

A counterexample in SturmLiouville completeness theory. (with Paul
Binding) Proceedings of the Royal Society of Edinburgh: Section A:
Mathematics 134 (2004) no. 2, 241248.

A contraction of the Lucas polygon. (with Vania Mascioni) Proceedings of the
American Mathematical Society 132 (2004) no. 10, 29732981.

Continuous embeddings, completions and complementation in Krein
spaces. (with Heinz Langer) Radovi Matematički 12 (2003) no. 1, 3779.

Standard symmetric operators in Pontryagin spaces: A generalized
von Neumann formula and minimality of boundary coefficients. (with
Tomas Azizov and Aad Dijksma) Journal of Functional Analysis 198
(2003) no. 2, 361412.

On the location of critical points of polynomials. (with Vania Mascioni) Proceedings of the
American Mathematical Society 131
(2003) no. 1, 253264.

Form domains and eigenfunction expansions for differential
equations with eigenparameter dependent boundary conditions. (with
Paul
Binding) Canadian Journal of Mathematics 54 (2002) no. 6, 11421164.

Discreteness of the spectrum of second order differential
operators and associated embedding theorems. (with Thomas T. Read)
Journal of Differential Equations, 184 (2002) no. 2, 526548.

The linearization of boundary eigenvalue problems and reproducing
kernel Hilbert spaces. (with Aad Dijksma and Tom Read) Linear Algebra and its Applications 329 (2001) no. 13, 97136.

On singular critical points of positive operators in Krein
spaces. (with Aurelian Gheondea and Heinz Langer) Proceedings of the
American Mathematical Society 128 (2000) no. 9, 26212626.

Boundary value problems in Krein spaces. Dedicated to the memory
of Branko Najman. Glasnik Matematički Ser. III 35(55) (2000)
no. 1, 4558.
Positive differential operators in Krein space $L^{2}({\mathbb R}^n)$. (with Branko Najman) Contributions to Operator Theory in
Spaces with an Indefinite Metric, The Heinz Langer Anniversary
Volume, 113129, Edited by A. Dijksma, I. Gohberg, M. A. Kaashoek, and R. Mennicken. Operator Theory: Advances and Applications, Vol. 106, Birkhäuser, 1998.

Examples of positive operators in Krein space with $0$ a regular
critical point of infinite rank. (with Branko Najman) 5156,
Operator Theory: Advances and Applications, Vol. 102,
Birkhäuser, Basel, 1998.

Preservation of the range under perturbations of an operator.
(with Branko Najman) Proceedings of the
American Mathematical Society
125 (1997) no. 9, 26272631.
Positive differential operators in Krein space
$L^{2}({\mathbb R})$. (with Branko Najman) Recent developments in operator theory and its applications (Winnipeg, MB, 1994), 95104, Operator Theory: Advances and Applications, Vol. 87, Birkhäuser, Basel, 1996.

Quadratic eigenvalue problems. (with Branko Najman) Mathematische
Nachrichten 174 (1995) 5564.

Quasiuniformly positive operators in Krein space. (with Branko
Najman) Operator theory and boundary eigenvalue problems (Vienna,
1993), 9099, Operator Theory: Advances and Applications, Vol.
80, Birkhäuser, Basel, 1995.
The operator $(\mbox{sgn}\,x)\frac{d^{2}}{dx^{2}}$ is similar to a
selfadjoint operator in $L^{2}({\mathbb R})$. (with Branko Najman)
Proceedings of the
American Mathematical Society 123 (1995) no. 4,
11251128.

A Krein space approach to elliptic eigenvalue problems with
indefinite weights. (with Branko Najman) Differential and Integral Equations
7 (1994) no. 56, 12411252.

Definitizable extensions of positive symmetric operators in a
Krein space. Integral Equations and Operator Theory 12 (1989) no. 5,
615631.

Characteristic functions of unitary colligations and bounded
operators in Krein spaces. (with Aad Dijksma, Heinz Langer, Henk S.V. de
Snoo) in The Gohberg Anniversary Collection, Vol. II, 125152,
Edited by H. Dym, S. Goldberg, M. A. Kaashoek, P. Lancaster,
Operator Theory: Advances and Applications, Vol. 41,
Birkhäuser Verlag, Basel, (1989).

A Krein space approach to symmetric ordinary differential
operators with an indefinite weight function. (with Heinz Langer)
Journal of Differential Equations 79 (1989) no. 1, 3161.

On the regularity of the critical point infinity of definitizable
operators. Integral Equations and Operator Theory 8 (1985) no. 4,
462488.

Nonmeasurable sets and pairs of transfinite sequences. (with Harry I.
Miller) Akad. Nauka Umjet. Bosne Hercegov. Rad. Odjelj. Prirod.
Mat. Nauka LXIX (1982) 3943.