1. A.Kutoglu, C.Scheringer, H.Meyer, and A.Schweig, Acta Cryst. 1981, in press.
2. R.Brill, Solid State Physics 20;1 (1967).
3. R.A.Bonham, Record of Chemical Progress 30:185 (1969).
4. Several articles in: “Transaction of the American Crystallographic Association”, Proceedings of the Symposium on “Experimental and Theoretical Studies of Electron Densities”, Albuquerque, New Mexico (1972).
5. R.F.Stewart, “Critical Evaluation of Chemical and Physical Structural Information”, National Academy of Sciences, Washington, D.C. (1974), p.540.