1. T. Otsu, A. Matsumoto, T. Kubota, S. Mori, Polym. Bull., 23, 45 (1990).
2. A. Matsumoto, T. Kubota, T. Otsu, Macromolecules, in press.
3. A. Matsumoto, T. Kubota, S. Mori, T. Otsu, in preparation.
4. T. Otsu, A. Tatsumi, A. Matsumoto, J. Polym. Sci., Polym. Lett. Ed., 24, 113 (1986).
5. S. R. Turner, K. D. Ahn, C. G. Willson, ACS Symposium Series 346; American Chemical Society, Washington, DC, 1987, p 200.