@article{UZKU_2016_158_4_a6,
     author = {R. Pirov},
     title = {On some overdetermined systems of three differential equations in second-order partial derivatives},
     journal = {U\v{c}\"enye zapiski Kazanskogo universiteta. Seri\^a Fiziko-matemati\v{c}eskie nauki},
     pages = {544--556},
     publisher = {mathdoc},
     volume = {158},
     number = {4},
     year = {2016},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZKU_2016_158_4_a6/}
}