Uniqueness/nonuniqueness for nonnegative solutions of a class of second-order parabolic equations. (English). In: Fila, Marek, Handlovičová, A., Mikula, K., Medveď, Milan, Quittner, Pavol and Ševčovič, Daniel (eds.): Proceedings of Equadiff 11, International Conference on Differential Equations. Czecho-Slovak series, Bratislava, July 25-29, 2005. [Part 2] Minisymposia and contributed talks. Comenius University Press, Bratislava, 2007. pp. 67-76