[1] A. ALEXIEWICZ W. ORLICZ: Analytic operations in real Banach spaces. Studia Math. XIV (1954), 47-78. MR 0062947

[2] S. FUČÍK: Note on the Fredholm alternative for nonlinear operators. Comment. Math. Univ. Carolinae 12 (1971), 213-226. MR 0288641

[3] S. FUČÍK O. JOHN J. NEČAS: Schauder bases in Sobolev spaces. Comment. Math. Univ. Carolinae 13 (1972), 163-175. MR 0306890

[4] S. FUČÍK J. NEČAS: Ljusternik-Schnirelman theorem and nonlinear eigenvalue problems. Math. Nachr. 53 (1972), 277-289. MR 0333863

[5] S. FUČÍK J. NEČAS J. SOUČEK V. SOUČEK: Upper bound for the number of critical levels for nonlinear operators in Banach spaces of the type of second order nonlinear partial differential operators. Journ. Funct. Anal. 11 (1972), 314-333. MR 0341224

[6] S. FUČÍK J. NEČAS J. SOUČEK V. SOUČEK: Note to nonlinear spectral theory: Application to the nonlinear integral equations of the Lichtenstein type. (to appear).

[7] S. FUČÍK J. NEČAS J. SOUČEK V. SOUČEK: Spectral analysis of nonlinear operators. Lecture notes in mathematics No 346, Springer 1973. MR 0467421

[8] E. HILLE R. PHILLIPS: Functional analysis and semigroups. Providence 1957.

[9] J. NEČAS: Fredholm theory of boundary value problems for nonlinear ordinary differential operators. Theory of Nonlinear Operators, Proceedings of a Summer School held in September 1971 at Babylon-Czechoslovakia, pp. 85-120, Academia, Prague 1973. MR 0402562

[10] M. M. VAJNBERG: Variational methods for the study of nonlinear operators. Holden-Day, 1964. Zbl 0122.35501