1. Burnham, C.W., Buerger, M.J.: Z. Kristallogr. 115, 269 (1961)
2. Langer, K., Abu-Eid, R.M.: Phys. Chem. Min. 1, 273 (1977)
3. Faye, G.H., Nickel, E.H.: Can. Mineral. 10, 35 (1969)
4. Faye, G.H., Harris, D.C.: ibid. 10, 47 (1969)
5. Moore, R.K., White, W.B.: ibid. 11, 791 (1972)