@article{DE_1966_2_9_a14,
     author = {V. R. Fridlender},
     title = {Generalization of the {Leibniz{\textendash}H\"ormander} formula. {Multiplication} of differential operators with variable coefficients},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1275--1276},
     year = {1966},
     volume = {2},
     number = {9},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1966_2_9_a14/}
}