1. V. P. Emelin and Yu. M. Kessler, Zh. Strukt. Khim.,13, 323 (1972).
2. N. S. Kurnakov, Introduction to Physicochemical Analysis [in Russian], Izd-vo AN SSSR, Moscow-Leningrad (1940).
3. G. Ebert and J. Wendorf, Ber. Bunsenges. Phys. Chem.,74, 1071 (1970).
4. P. Assarsson, J. Phys. Chem.,72, 2710 (1968).
5. N. I. Larionov, N. A. Dmitrieva, and G. V. Goryachko, Use of Ultrasonics to Investigate Materials [in Russian], No. VII, Izd-vo MOGPI, Moscow (1958), p. 51.