1. B.D. Steele, F.M.G. Johnson, J. Chemical Soc. 85, 113 (1904)
2. J.I. Jambor, D.K. Nordstrom, C.N. Alpers, Sulfate Minerals-Crystallography, Geochemistry and Environmental Significance 40, 303 (2000)
3. J.L. Janjic, M. Gakovic, D. Dordevic, P. Bugarski, Chem. Abstracts 95, 5 (1980)
4. F.C. Hawthorne, Zeitschrift für Kristallographie 192, 1 (1990)
5. F.C. Hawthorne, S.V. Krivovichev, P.C. Burns, Sulfate Minerals-Crystallography, Geochemistry and Environmental Significance 40, 1 (2000)