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@article{DAN_1966_168_3_a1, author = {B. D. Annin}, title = {A certain property of a solution of the equation $u_{xx}u_{yy}-u_{xy}^2=1$}, journal = {Doklady Akademii Nauk}, pages = {499--501}, publisher = {mathdoc}, volume = {168}, number = {3}, year = {1966}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1966_168_3_a1/} }
B. D. Annin. A certain property of a solution of the equation $u_{xx}u_{yy}-u_{xy}^2=1$. Doklady Akademii Nauk, Tome 168 (1966) no. 3, pp. 499-501. http://geodesic.mathdoc.fr/item/DAN_1966_168_3_a1/