@article{IVM_1977_10_a8,
     author = {Ju. M. Krikunov},
     title = {On the {Tricomi} problem for a~square},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {81--85},
     publisher = {mathdoc},
     number = {10},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1977_10_a8/}
}