Hypersonic wave anomalies in Cs3H(SeO4)2 at the transitions above room temperature Y. Luspin, D. De Sousa Meneses, P. Simon and G. Hauret Eur. Phys. J. B, 10 2 (1999) 215-221 Published online: 15 July 1999 DOI: 10.1007/s100510050848