@article{PORMA_1994__51_4_47349,
     author = {Ramos, M. and Rebelo, C.},
     title = {A unified approach to min-max critical point theorems.},
     journal = {Portugaliae mathematica},
     pages = {489--516},
     publisher = {mathdoc},
     volume = {51},
     number = {4},
     year = {1994},
     zbl = {0831.58014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1994__51_4_47349/}
}