@article{10_21136_CPM_1987_118308,
     author = {Medkov\'a, Dagmar},
     title = {Note on contractivity of the {Neumann} operator},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky},
     pages = {197--208},
     publisher = {mathdoc},
     volume = {112},
     number = {2},
     year = {1987},
     doi = {10.21136/CPM.1987.118308},
     mrnumber = {897645},
     zbl = {0657.31010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPM.1987.118308/}
}