1. I. N. Adamenko, K. E. Nemchenko, and V. I. Tsyganok. J. of Low Temp. Phys. 81 (1990) 233.
2. I. N. Adamenko, K. E. Nemchenko, V. I. Tsyganok, and A. I. Chervanyov. Fiz. Niz. Temp. 20 (1994) 636.
3. I. M. Khalatnikov and V. N. Zharkov. Zh. Eksp. Teor. Fiz. 32 (1957) 1108.
4. B. N. Esel’son, V. G. Ivantsov, V. A. Koval, E. Ya. Rudavskii, and I. A. Serbin Properties of Solid and Liquid Helium [in Russian], Naukova Dumka, Kiev (1982).
5. Y. E. Opfee, K. Luszczynski, and R. E. Norberg. Phys. Rev. 172 (1968) 192.