@article{MZ_1991__206_1_174243,
     author = {E.N. Dancer},
     title = {On the number of positive solutions of some weakly nonlinear equations on annular regions.},
     journal = {Mathematische Zeitschrift},
     pages = {551--562},
     publisher = {mathdoc},
     volume = {206},
     number = {1},
     year = {1991},
     zbl = {0705.35043},
     url = {http://geodesic.mathdoc.fr/item/MZ_1991__206_1_174243/}
}