1. G. I. Barenblatt and S. A. Khristianovich, “Roof collapse in mine workings,” Izv. Akad. Nauk SSSR, Otd. Tekh. Nauki, No. 11, (1955).
2. I. M. Petukhov, A. M. Linkov, et al., Protective Seam Theory [in Russian], Nedra, Moscow (1976).
3. R. P. Fedorenko, Approximate Solution of Optimum Control Problems [in Russian], Nauka, Moscow (1978).
4. R. V. Gol’dshtein and A. S. Zazovskii, “Numerical method for solving spatial problems of elasticity theory for bodies with plane sections and depressed cavities,” Preprint No. 192, IPM Akad. Nauk SSSR, Moscow (1982).
5. R. V. Gol’dshtein and A. A. Spektor, “Variational estimates for solution of some composite spatial problems of elasticity theory with an unknown boundary,” Izv. Akad. Nauk SSSR, Mekh. Tverd. Tela, No. 2 (1978).