@article{DE_1970_6_7_a19,
     author = {N. Z. Gabbasov and E. S. Chichkin},
     title = {The estimation of the domains of nonnegativity of the {Cauchy} function and its derivatives up to order $n-1$ for an $n$th order ordinary linear differential equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1308--1310},
     publisher = {mathdoc},
     volume = {6},
     number = {7},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_7_a19/}
}