@article{DE_1993_29_8_a20,
     author = {E. V. Antipova},
     title = {On the incompleteness of the system of root functions of the {Tricomi} problem for the {Lavrent'ev--Bitsadze} equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1451--1452},
     publisher = {mathdoc},
     volume = {29},
     number = {8},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1993_29_8_a20/}
}