Petryshyn, W. V. Using degree theory for density defined A-proper maps in the solvability of semilinear equations with unbounded and noninvertible linear part. (English) Zbl 0444.47046 Nonlinear Anal., Theory Methods Appl. 4, 259-281 (1980). MSC: 47J05 PDF BibTeX XML Cite \textit{W. V. Petryshyn}, Nonlinear Anal., Theory Methods Appl. 4, 259--281 (1980; Zbl 0444.47046) Full Text: DOI
Mawhin, J.; Schmitt, K. Rothe and Altman type coincidence theorems and applications to differential equations. (English) Zbl 0347.34028 Nonlinear Anal., Theory, Methods Appl. 1, 151-160 (1977). MSC: 34C25 47J05 PDF BibTeX XML Cite \textit{J. Mawhin} and \textit{K. Schmitt}, Nonlinear Anal., Theory Methods Appl. 1, 151--160 (1977; Zbl 0347.34028) Full Text: DOI
Tucker, T. S. Leray-Schauder theorem for P-compact operators and its consequences. (English) Zbl 0167.44701 J. Math. Anal. Appl. 23, 355-364 (1968). PDF BibTeX XML Cite \textit{T. S. Tucker}, J. Math. Anal. Appl. 23, 355--364 (1968; Zbl 0167.44701) Full Text: DOI