@article{AUPO_1991__30_1_a16,
     author = {Fut\'ak, J\'an},
     title = {On the existence of solutions of operator-differential equations},
     journal = {Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica},
     pages = {203--210},
     publisher = {mathdoc},
     volume = {30},
     number = {1},
     year = {1991},
     mrnumber = {1166437},
     zbl = {0757.34053},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPO_1991__30_1_a16/}
}