1. Hydrogen substituted by helium(+): theoretical investigations on the structures and stabilities of He2O2+, He2N2+, and He2C2+
2. W. Koch and G. Frenking, Intern. J. Mass Spectrom. Ion Processes, to be published.
3. W. Koch, J. Collins, G. Frenking, J. Gauss and D. Cremer, manuscript in preparation.
4. The structure of CCH+
5. J.S. Binkley, M.J. Frisch, K. Raghavachari, R.A. Whiteside, H.B. Schlegel, E.M. Fluder, and J.A. Pople, Camegie-Mellon University, Pittsburgh (1984).