@article{VUU_2020_30_1_a2,
     author = {K. T. Karimov},
     title = {Keldysh problem for a three-dimensional equation of mixed type with three singular coefficients in a semi-infinite parallelepiped},
     journal = {Vestnik Udmurtskogo universiteta. Matematika, mehanika, kompʹ\^uternye nauki},
     pages = {31--48},
     publisher = {mathdoc},
     volume = {30},
     number = {1},
     year = {2020},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VUU_2020_30_1_a2/}
}