1. Sheppard, R.A., Gude, A.J., Hay, R.L.: Am. Mineralogist 55 (1970) 358–363.
2. McAtee jr., J.L., House, R., Eugsten, H.P.: Am. Mineralogist 53(1968)2061–2069.
3. Brindley, G.W.: Am. Mineralogist 54(1969)1583–1591.
4. Eugster, H.P.˜ Science 157 (1967) 1177–1180.
5. Hay, R.L.: Contnib. Mineral. Petrology (Berlin) 17 (1968) 255–274.