Characterisation and phase transitions in a new mixed acid sulphate K0.9Rb0.1HSO4 H. Guermazi, M. Bouachir, Y. Mlik and T. Mhiri Eur. Phys. J. AP, 18 2 (2002) 99-107 Published online: 15 May 2002 DOI: 10.1051/epjap:2002031