Global Instability and Essential Spectrum in Semilinear Evolution Equations. J. Solà-Morales — 1986 Mathematische Annalen
Asymptotic behavior of solutions of semilinear elliptic equations on an unbounded strip. Brunovský, P.; Mora, X.; Poláčik, P.; Solà-Morales, J. — 1991 Acta Mathematica Universitatis Comenianae. New Series