@article{10_4064_fm176_3_3,
     author = {Marek Izydorek and Krzysztof P. Rybakowski},
     title = {Multiple solutions of indefinite elliptic systems
  via a {Galerkin-type} {Conley} index theory},
     journal = {Fundamenta Mathematicae},
     pages = {233--249},
     publisher = {mathdoc},
     volume = {176},
     number = {3},
     year = {2003},
     doi = {10.4064/fm176-3-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm176-3-3/}
}