Citation: Percival, M. J. L.; Schmahl, W. W.; Salje, E. (1989). Structure of cobalt doped K2Cd2(SO4)3 langbeinite at three temperatures above the P2_13-P2_12_12_1 phase transition, and a new trigger mechanism for the ferroelastic transformation Sample: T = 640 K. Physics and Chemistry of Minerals, 16, pp. 569-575.