@article{MZM_1989_45_5_a1,
     author = {A. V. Isaev},
     title = {Reduction of the problem of the classification of tubular quadrics to the solving of a system of differential equations of a special form},
     journal = {Matemati\v{c}eskie zametki},
     pages = {10--18},
     publisher = {mathdoc},
     volume = {45},
     number = {5},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1989_45_5_a1/}
}