@article{10_14708_cm_v20i2_5903,
     author = {J. Go{\l}\k{a}b},
     title = {On a certain mixed boundary value problem for iterated {Helmholtz} equation},
     journal = {Commentationes Mathematicae},
     pages = { 323--336},
     publisher = {mathdoc},
     volume = {20},
     number = {2},
     year = {1978},
     doi = {10.14708/cm.v20i2.5903},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v20i2.5903/}
}