1. [1] W. Arveson, Notes on extensions of $C\sp\sp*$-algebras, Duke Math. J. 44 (1977), no. 2, 329–355.
2. [2] E. G. Effros and J. Rosenberg, $C\sp\ast$-algebras with approximately inner flip, Pacific J. Math. 77 (1978), no. 2, 417–443.
3. [3] P. R. Halmos, Ten problems in Hilbert space, Bull. Amer. Math. Soc. 76 (1970), 887–933.
4. [4] E. Kirchberg, in preparation.
5. [5] G. K. Pedersen, $C\sp\ast$-algebras and their automorphism groups, London Mathematical Society Monographs, vol. 14, Academic Press Inc. [Harcourt Brace Jovanovich Publishers], London, 1979.