1. Abstract critical point theorems and applications to some nonlinear problems with strong resonance at infinity;Bartolo;Nonlinear Anal. TMA,1983
2. Applications of homology theory to some problems in differential equations;Chang,1986
3. On the Periodic Nonlinearity and the Multiplicity Solutions;Chang;University of Wisconsin-Madison, Center for the Mathematical Sciences, Technical Summary Report, No. 88-19,1987
4. A note on a resonance problem;Lupo,1986
5. Forced second order conservative system with periodic nonlinearity;Mawhin,1987