1. G. I. Barenblatt and A. Yu. Ishlinskii, “On the impact of a viscoelastic rod upon a rigid obstacle,” Prikl. Mat. Mekh.,26, No. 3, 497–502 (1962).
2. S. N. Kruzhkov, “Some problems with unknown boundary for the heat-conduction equation,” Prikl. Mat. Mekh.,31, No. 6, 1009–1020 (1967).
3. S. N. Kruzhkov and S. Yakubov, “On the solvability of one class of problems with unknown boundary for the heat-conduction equation and the behavior of solutions as time infinitely increases,” Dinam. Sploshn. Sred., Issue 36, 46–70 (1978).
4. A. Fasano and M. Primicerio, “Viscoplastic impact of a rod on a wall,” Boll. Unione Mat. Ital. Ser. 4,7, No. 3, 531–555 (1975).
5. J. Takhirov and R. Turaev, “The free boundary problem without initial condition,” J. Math. Sci.,187, No. 1, 86–100 (2012).