1. H. M. Powell,J. Chem. Soc, 61–73 (1948).
2. E. Weber and H.-P. Josel,J. Incl. Phenom.,1, No. 1, 79–85 (1983).
3. Yu. A. Simonov, M. S. Fonari, J. Lipkowski, et al.,J. Incl. Phenom.,24, 149–161 (1996).
4. S. J. Loeb, in:Comprehensive Supramolecular Chemistry, Vol. 1, J. L. Atwood, J. E. D. Davies, D. D. MacNicol, and J.-M. Lehn (eds.). Pergamon (1996), pp. 733–753.
5. G. M. Sheldrick,SHELXS-85. Program for Crystal Structure Determination, University of Göttingen, Germany.