Mawhin, Jean: Critical point theory and nonlinear differential equations.
(English).
In:
Vosmanský, Jaromír
and Zlámal, Miloš (eds.): Equadiff 6.
Proceedings of the International Conference on Differential Equations and Their Applications held in Brno, Czechoslovakia, Aug. 26 - 30, 1985.
J. E. Purkyně University, Department of Mathematics, Brno, 1986.
pp. 49-58
