@article{MMO_2021_82_2_a4,
     author = {A. V. Tsvetkova and A. I. Shafarevich},
     title = {The wave equation with symmetric velocity on the hybrid manifold obtained by gluing a ray to a three-dimensional sphere},
     journal = {Trudy Moskovskogo matemati\v{c}eskogo ob\^{s}estva},
     pages = {369--392},
     publisher = {mathdoc},
     volume = {82},
     number = {2},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MMO_2021_82_2_a4/}
}