1. (1) J. E. Keith, G. D. Badhwar, and D. J. Lindstrom, Nucl. Tracks. Radiat. Meas. 20, 41 (1992).
2. (2) V. Dudkin, Y. V. Potapov, A. B. Akopova, L. V. Melkumyan, E. V. Benton, and A. L. Frank, Nucl. Tracks. Radiat. Meas. 17, 87 (1990).
3. (3) A. P. Labakov, V. I. Lyagushin, M. I. Panasyuk, V. M. Petrov. and P. I. Shavrin, Nucl. Tracks. Radial. Meas. 20, 55 (1992).
4. (4) N. Nakao, T. Nakamura, M. Baba, Y. Uwamino, N. Nakanishi, H. Nakashima, and Sh. Tanaka, Nucl. Instr. and Meth. A362, 454 (1995).
5. (5) N. Nakao, T. Kurosawa, T. Nakamura, and Y. Uwamino, Nucl. Instr. and Meth. A463, 275 (2001).