@article{ARM_2004_40_4_a11,
     author = {Fi\v{s}narov\'a, Simona},
     title = {Oscillatory properties of fourth order self-adjoint differential equations},
     journal = {Archivum mathematicum},
     pages = {457--469},
     year = {2004},
     volume = {40},
     number = {4},
     mrnumber = {2129965},
     zbl = {1117.34038},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_2004_40_4_a11/}
}