Observation of a Kosterlitz-Thouless state at the spin-Peierls phase transition in
J. E. Lorenzo, L. P. Regnault, S. Langridge, C. Vettier, C. Sutter, G. Grübel, J. Souletie, J. G. Lussier, J. P. Schoeffel, J. P. Pouget, A. Stunault, D. Wermeille, G. Dhalenne and A. Revcolevschi
