@article{10_14708_cm_v11i1_5617,
     author = {E. \'Sliwi\'nski},
     title = {On some oscillation problems for elliptic equations of fourth order},
     journal = {Commentationes Mathematicae},
     pages = { 199--203},
     publisher = {mathdoc},
     volume = {11},
     number = {1},
     year = {1968},
     doi = {10.14708/cm.v11i1.5617},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v11i1.5617/}
}