1. On the structure of spectra of travelling waves;Simon;EJQTDE,2003
2. Shape-preserving time-dependences in heat conduction;Farkas;Acta Phys. Hung.,1984
3. Maximum Principles in Differential Equations;Protter,1967
4. Elliptic Partial Differential Equations of Second Order;Gilbarg,1977
5. Linear and Quasilinear Elliptic Equations;Ladyzhenskaya,1968