Siberian Mathematical Journal
Siberian Mathematical Journal > 2017 > 58 > 4 > 672-675
Siberian Mathematical Journal > 2017 > 58 > 5 > 794-800
Siberian Mathematical Journal > 2017 > 58 > 4 > 672-675
Siberian Mathematical Journal > 2017 > 58 > 5 > 794-800