1. D. Watkins, K. Dircks and D. Epp, 1988 FC Seminar, 1988, p. 350
2. D. Watkins, 4th Annual Battery Conference, Long Beach, CA, 1989
3. M. Yoshitake, M. Tamura and T. Ishisaki, FCDIC 1'st Symposium, 1994, p. 154
4. N. Yoshida, T. Ishisaki and M. Yoshitake, FCDIC 2'nd Symposium, 1995, p. 220
5. M. Yoshitake, N. Yoshida and T. Ishisaki, FCDIC 3rd Symposium, 1996, p. 296