@article{10_14708_cm_v19i1_5833,
     author = {F. Bara\'nski},
     title = {The mean value theorem and oscillatory properties of certain elliptic equations in three dimensional space},
     journal = {Commentationes Mathematicae},
     pages = { 13--14},
     publisher = {mathdoc},
     volume = {19},
     number = {1},
     year = {1976},
     doi = {10.14708/cm.v19i1.5833},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v19i1.5833/}
}