1. Hlásnik I., Takács S.:in Proc. of Int. Conf. on Magnet Technology MT-9 (Eds. P. Weymuth and C. Marinucci), Zürich 1985, p. 481.
2. Yamafuji K.:in Proc. Int. Symp. on Flux Pinning and Electromagn. Prop. in Super-conductors (Eds. T. Matsushita, K. Yamafuji and F. Irie). Matsukama Press Co., Fukuoka, 1985, p. 18.
3. Takács S.: Czech. J. Phys. B36 (1986) 524.
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5. Takács S.: in [2], p. 204.