1. B. O. Wells, Y. S. Lee, M. A. Kastner, R. J. Christianson, R. J. Birgeneau, Department of Physics, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
2. K. Yamada and Y. Endoh, Department of Physics, Tohoku University, Aramaki Aoba, Sendai, 980-77, Japan.
3. G. Shirane, Department of Physics, Brookhaven National Laboratory, Upton, NY 11973, USA.