1. V. I. Gorbachuk and M. L. Gorbachuk, ?On boundary values of solutions of homogeneous differential equations,? Dokl. Akad. Nauk SSSR,228, No. 5, 1021?1024 (1976).
2. V. I. Gorbachuk and M. L. Gorbachuk, ?Some topics of spectral theory of elliptic differential equations in space of vector functions in finite interval,? Ukr. Mat. Zh.,28, No. 1, 12?26 (1976).
3. V. I. Gorbachuk and M. L. Gorbachuk, ?Some topics of spectral theory of elliptic differential equations in space of vector functions,? ibid., No. 3, 313?324.
4. V. I. Gorbachuk and M. L. Gorbachuk, ?Boundary values of solutions of some classes of differential equations,? Mat. Sb.,101, No. 1, 124?150 (1977).
5. Yu. M. Berezanskii, Eigenfunction Expansion of Self-Adjoint Operators [in Russian], Naukova Dumka, Kiev (1965).