Hlaváček, Ivan: Some variational methods for nonlinear mechanics.
(English).
In:
Fučík, Svatopluk
and Kufner, Alois (eds.): Nonlinear Analysis, Function Spaces and Applications, Proceedings of a Spring School held in Horní Bradlo, 1978.
[Vol 1].
BSB B. G. Teubner Verlagsgesellschaft, Leipzig, 1979.
pp. 128-148