On the time periodic free boundary associated to some nonlinear parabolic equations. Badii, M.; Díaz, J.I. — 2010 Boundary Value Problems [electronic only]
Existence and attractivity results for a class of degenerate functional-parabolic problems M. Badii; J. I. Diaz; A. Tesei — 1987 Rendiconti del Seminario Matematico della Università di Padova