no. 4
Multiple critical points for variational problems on partially ordered Hilbert spaces
Annales de l'I.H.P. Analyse non linéaire, Tome 7 (1990) no. 4, pp. 287-304. 
@article{AIHPC_1990__7_4_287_0,
     author = {Wysocki, K.},
     title = {Multiple critical points for variational problems on partially ordered {Hilbert} spaces},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {287--304},
     publisher = {Gauthier-Villars},
     volume = {7},
     number = {4},
     year = {1990},
     mrnumber = {1067777},
     zbl = {0709.58013},
     language = {en},
     url = {http://www.numdam.org/item/AIHPC_1990__7_4_287_0/}
}
TY  - JOUR
AU  - Wysocki, K.
TI  - Multiple critical points for variational problems on partially ordered Hilbert spaces
JO  - Annales de l'I.H.P. Analyse non linéaire
PY  - 1990
SP  - 287
EP  - 304
VL  - 7
IS  - 4
PB  - Gauthier-Villars
UR  - http://www.numdam.org/item/AIHPC_1990__7_4_287_0/
LA  - en
ID  - AIHPC_1990__7_4_287_0
ER  - 
%0 Journal Article
%A Wysocki, K.
%T Multiple critical points for variational problems on partially ordered Hilbert spaces
%J Annales de l'I.H.P. Analyse non linéaire
%D 1990
%P 287-304
%V 7
%N 4
%I Gauthier-Villars
%U http://www.numdam.org/item/AIHPC_1990__7_4_287_0/
%G en
%F AIHPC_1990__7_4_287_0
Wysocki, K. Multiple critical points for variational problems on partially ordered Hilbert spaces. Annales de l'I.H.P. Analyse non linéaire, Tome 7 (1990) no. 4, pp. 287-304. http://www.numdam.org/item/AIHPC_1990__7_4_287_0/

[1] H. Amann, Fixed point equations and nonlinear eigenvalue problems in ordered Banach spaces. Siam Rev., t. 18, 1976, p. 620-709. | MR | Zbl

[2] S.B. Angenent, J. Mallet-Paret, L.A. Peletier, Stable transition layers in similinear boundary value problem. J. Diff. Eq., t. 62, 1986, p. 427-442.

[3] R. Bott, Lectures on Morse theory, old and new. Bull. Am. Math. Soc., t. 7, 1982, p. 331-358. | MR | Zbl

[4] E.N. Dancer, Multiple fixed points of positive mappings. J. Reine aug. Math., t. 371, 1986, p. 46-66. | MR | Zbl

[5] K. Deimling, Ordinary Differential Equations in Banach Spaces. Lect. Notes Math., vol. 596, Springer 1977. | MR | Zbl

[6] H. Hofer, Variational and topological methods in partially ordered Hilbert spaces. Math. Ann., t. 261, 1982, p. 493-514. | MR | Zbl

[7] H. Hofer, The topological degree at a critical point of moutain-pass type. Proceedings of Symposia in Pure Mathematics, vol. 45, 1986, p. 501-509. | MR | Zbl

[8] A. Marino, G. Prodi, Metodi perturbativi nella teoria di Morse. Boll. Un. Math. Ital., Suppl., 3, 1975, p. 1-32. | MR | Zbl