1. A. M. Nakhushev, “On nonlocal problems with shift and their connection with loaded equations,” Differents. Uravn., 21, No. 1, 92–101 (1985).
2. A. V. Bitsadze and A. A. Samarskii, “On some simplest generalizations of linear elliptic boundary-value problems,” Dokl. Akad. Nauk SSSR, 185, No. 4, 739–740 (1969).
3. P. N. Vabishchevich, “Nonlocal parabolic problem and inverse heat problem,” Differents. Uravn., 17, No. 7, 1193–1199 (1981).
4. I. Ya. Kmit’, “On one nonlocal problem for a quasilinear hyperbolic system of the first order with two independent variables,” Ukr. Mat. Zh., 45, No. 9, 1307–1311 (1993).
5. I. Ya. Kmit’ and S. P. Lavrenyuk, “On nonlocal problems for two-dimensional hyperbolic systems,” Usp. Mat. Nauk, 46, No. 6, 149 (1991).