@article{DE_1973_9_11_a14,
     author = {M. M. Smirnov},
     title = {The second boundary value problem for a certain fourth order equation of mixed type in the disc},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2052--2057},
     publisher = {mathdoc},
     volume = {9},
     number = {11},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_11_a14/}
}