1. Backhaus, S.et al. Nature 392, 687–690 (1998).
2. Pereversev, S. V., Loshak, A. Backhau, S., Davi, J. C. & Packard, R. E. Nature 338, 449–451 (1997).
3. Backhaus, S., Pereversev, S., Loshak, A., Davis, J. C. & Packard, R. E. Science 278, 1435(1997).
4. Varoquaux, E., Avenel, O., Ihas, G. & Salmelin, R. Physica B 178, 309–317 (1992).
5. Hatakanaka N. Phys. Rev. Lett. 81 17 17 (1998).