[1] W. L. Bond, Acta Cryst, 13 (1960)，p. 814.

[2] B. Cockayne, J. Crystal Growth, 3/4, (1968), p. 60.

[3] E. F. Belt, J. Crystal G_th，13/14 (1972), p. 268.

[4] В. Cockayne, J. Mater. Sci.，8 (1973)，p. 601.

[5] M. Kestigian, W. W. Holloway, J. Crystal Growth, 3/4 (1968), p. 455~457.

[6] В. Cockayne, J. Mater. Sci., 2 (1967)，p. 7.

[7] Cockayne, J. Mater. Sci., 1 (1966), p. 112.