@article{PORMA_1978__37_3-4_115359,
     author = {Taylor, W.E. jr.},
     title = {On the oscillation of a fourth order differential equation and its adjoint},
     journal = {Portugaliae mathematica},
     pages = {299--305},
     publisher = {mathdoc},
     volume = {37},
     number = {3-4},
     year = {1978},
     mrnumber = {0633035},
     zbl = {0504.34017},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1978__37_3-4_115359/}
}