1. 1) Noma, S., Saito, T., Ekino, T., Akimitsu, J. and Sueno, S. (1993) Superconducting phase in Nb1−xTaxSe3 (0.135 < x < 0.16). Phys. Rev. B 48, 9620–9627.
2. 2) Kawabata, K. (1985) Impurity effects on superconductivity and charge density waves in NbSe3. J. Phys. Soc. Jpn. 54, 762–770.
3. 3) Bednorz, J.G. and Müller, K.A. (1986) Possible high-Tc superconductivity in the Ba-La-Cu-O system. Z. Phys. B 64, 189–193.
4. 4) Wu, M.K., Ashburn, J.R., Torng, C.J., Hor, P.H., Meng, R.L., Gao, L. (1987) Superconductivity at 93 K in a new mixed-phase Y-Ba-Cu-O compound system at ambient pressure. Phys. Rev. Lett. 58, 908–910.
5. 5) Akimitsu, J., Yamazaki, A., Sawa, H. and Fujiki, H. (1987) Superconductivity in the Bi-Sr-Cu-O system. Jpn. J. Appl. Phys. 26, L2080–L2081.