@article{VMUMM_2004_6_a1,
     author = {I. A. Rudakov},
     title = {Periodic radially symmetric solution of a nonlinear wave equation in a ball},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {8--14},
     publisher = {mathdoc},
     number = {6},
     year = {2004},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2004_6_a1/}
}