@article{10_21136_CPM_1985_108593,
     author = {Krej\v{c}{\'\i}, Pavel},
     title = {Periodic solutions of a class of abstract nonlinear equations of the second order},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky},
     pages = {122--129},
     publisher = {mathdoc},
     volume = {110},
     number = {2},
     year = {1985},
     doi = {10.21136/CPM.1985.108593},
     mrnumber = {796562},
     zbl = {0574.34024},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPM.1985.108593/}
}