@article{IVM_1981_9_a19,
     author = {O. M. Teut},
     title = {A~problem for a~system of mixed-composite type in a~characteristic quadrangle},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {81--84},
     publisher = {mathdoc},
     number = {9},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1981_9_a19/}
}