ON SOME PROPERTIES OF THE SHORTEST CURVE IN A COMPOUND DOMAIN Статья Davydova A.V., Karamzin D.Y. Differential Equations. Том Vol 51 Iss 12. 2015.
ON THE CAUCHY–GELFAND PROBLEM Статья Henkin G.M., Shananin A.A. Doklady Mathematics. Том Vol 92 Iss 3. 2015. С. 731-734