1. J Akimitsu, Symposium on transition metal oxides, January 10 (2001) (Sendai, Japan)
2. Y Nagamatsu, N Nakagawa, T Murunaka, Y, Zenitani and J Akimitsu, Nature 410, 63 (2001)
3. S L Bud’ko, G Lapertot, C Petrovic, C E Cunningham, N Anderson and P C Canfield, Phys. Rev. Lett. 86, 1877 (2001)
4. S L Li, H H Wen, Z W Zhao, Y M Ni, Z A Ren, G C Che, H P Yang, Z Y Liu and Z X Zhao, cond-mat/0103032 (2001)
5. C-T Chen, P Seneor, N-C Yeh, R P Vasquez, C U Jung, Min-Seok Park, Heon-Jung Kim, W N Kang and Sung-Ik Lee, cond-mat/0104285 (2001)