1. L. C. Fatterly, in:Non-Stoichiometric Compounds, L. Mandelcorn (ed.), Academic Press, New York (1964).
2. G. N. Chekhova, Candidate’s Dissertation, Novosibirsk (1978).
3. M. D. Hollingsworth and K. D. M. Harris, in:Comprehensive Supramolecular Chemistry, Vol. 6, J. L. Atwood, J. E. D. Davies, and D. D. MacNicol (eds.) (1966), pp. 177–237.
4. Yu. A. Dyadin, I. V. Bondaryuk, and L. S. Aladko,Zh. Strukt. Khim.,36, No. 6, 1088–1141 (1995).
5. H.-U. Lenne,Acta Crystallogr.,7, 1–17 (1954).