1. A.C. Lazer, P.J. McKenna, Large-amplitude periodic oscillations in suspension bridges: some new connections with nonlinear analysis, SIAM Review 32 (1990) 537–578.
2. G. Tarantello, A note on a semilinear elliptic problem, Diff. Integ. Equat. 5(3) (1992) 561–565.
3. A.C. Lazer, P.J. McKenna, Global bifurcation and a theorem of Tarantello, J. Math. Anal. Appl. 181 (1994) 648–655.
4. Multiplicity results for a fourth-order semilinear elliptic problem;Micheletti;Nonlinear Analysis,1998
5. Convex Analysis and Variational Problems;Ekeland,1976