[1] CESARI L.: Functional analysis, nonlinear differential equations and the alternative method. In: Nonlinear Functional Analysis and Differential Equations (L. Cesari, R. Kannan, J.D. Schuur, eds.), Marcel Dekker Inc., New York, 1976, pp. 1-198. MR 0487630

[2] DALECKIǏ J. L., KREǏN M. G.: Stability of Solutions of Differential Equations in Banach Spaces. (Russian), Nauka, Moscov, 1970. MR 0352638

[3] DEFIGUEIREDO D. G.: On the range of nonlinear operators with linear asymptotes which are not invertible. Comment. Math. Univ. Carolin. 15 (1974), 415-428. MR 0365254

[4] DRÁBEK P.: Landesman-Lazer condition and nonlinearities with linear growth. Czechoslovak Math. J. 40(115) (1990), 70-87. MR 1037351

[5] DUGUNDJI J., GRANAS A.: Fixed Point Theory. Vol. I, PWN, Warsaw, 1981.

[6] FUČÍK S.: Solvability of Nonlinear Equations and Boundary Value Problems. D. Reidel Publ. Comp., Dordrecht, 1980. MR 0620638

[7] FURI M.-PERA P.: An elementary approach to boundary value problems at resonance. Nonlinear Anal. 4 (1980), 1081-1089. MR 0591301 | Zbl 0454.47054

[8] IANNACCI R., NKASHAMA M. N.: Nonlinear two-point boundary value problems at resonance without Landesman-Lazer condition. Proc. Amer. Math. Soc. 106 (1989), 943-952. MR 1004633 | Zbl 0684.34025

[9] KANNAN R.: Perturbation methods for nonlinear problems at resonance. In: Nonlinear Functional Analysis ... (see [1]) pp. 209-226. MR 0492478 | Zbl 0356.34057

[10] LANDESMAN E. M., LAZER A. C.: Nonlinear perturbations of linear elliptic boundary value problems at resonance. J. Math. Mech. 19 (1970), 609-623. MR 0267269 | Zbl 0193.39203

[11] MAWHIN J.: Topological degree methods in nonlinear boundary value problems. In: Regional Conf. Series in Math. 40, Amer. Math. Soc., Providence R.I., 1979. MR 0525202 | Zbl 0414.34025

[12] PRZERADZKI B.: An abstract version of the resonance theorem. Ann. Polon. Math. 53 (1991), 35-43. MR 1110659 | Zbl 0746.47043

[13] PRZERADZKI B.: Operator equations at resonance with unbounded nonlinearities. Preprint. MR 1404067 | Zbl 0881.47045

[14] PRZERADZKI B.: A new continuation method for the study of nonlinear equations at resonance. J. Math. Anal. Appl. 180 (1993), 553-565. MR 1251875 | Zbl 0807.34029

[15] PRZERADZKI B.: A note on solutions of semilinear equations at resonance in a cone. Ann. Polon. Math. 58 (1993), 95-103. MR 1215764 | Zbl 0776.34035

[16] PRZERADZKI B.: Three methods for the study of semilinear equations at resonance. Colloq. Math. 66 (1993), 109-129. MR 1242650 | Zbl 0828.47054

[17] WILLIAMS S. A.: A sharp sufficient condition for solution of a nonlinear elliptic boundary value problem. J. Differential Equations 8 (1970), 580-586. MR 0267267 | Zbl 0209.13003