@article{FAA_2004_38_2_a5,
     author = {I. V. Tikhonov},
     title = {Abstract {Differential} {Null-Equations}},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {65--70},
     publisher = {mathdoc},
     volume = {38},
     number = {2},
     year = {2004},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_2004_38_2_a5/}
}