Kawohl, B.: Overdetermined problems and the $p$-Laplacian.
(English).
In:
Fila, Marek, Mikula, K.
and Quittner, Pavol (eds.): Proceedings of Equadiff 11, International Conference on Differential Equations. Czecho-Slovak series, Bratislava, July 25-29, 2005.
[Part 1] Contributions of plenary speakers and minisymposia organizers.
Comenius University Press, Bratislava, 2007.
pp. 77-83