@article{INTO_2021_200_a6,
     author = {V. P. Kurdyumov and A. P. Khromov},
     title = {Divergent series and the mixed problem for the wave equation with free endpoints},
     journal = {Itogi nauki i tehniki. Sovremenna\^a matematika i e\"e prilo\v{z}eni\^a. Temati\v{c}eskie obzory},
     pages = {65--72},
     publisher = {mathdoc},
     volume = {200},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTO_2021_200_a6/}
}