@article{ZNSL_1991_188_a7,
     author = {E. V. Frolova},
     title = {On a non-stationary problem in a dihedral {angle.~I}},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {159--177},
     publisher = {mathdoc},
     volume = {188},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1991_188_a7/}
}