@article{MZM_1991_49_6_a20,
     author = {N. G. Khor'kova},
     title = {$\mathscr C$-spectral sequence of evolution equations},
     journal = {Matemati\v{c}eskie zametki},
     pages = {145--147},
     year = {1991},
     volume = {49},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1991_49_6_a20/}
}