1. Adachi, M., Okuyama, K., and Seinfeld, J H.: Experimental studies of ion-induced nucleation, J. Aerosol Sci., 23, 327–337, 1992.
2. Aplin, K L. and Harrion, R G.: A computer-controlled Gerdien atmospheric ion counter., Rev. Sci. Instrum., 71, 3037–3041, 2000.
3. Arnold, F.: Multi-ion complexes in the stratosphere – Implications for trace gases and aerosol, Nature, 284, 610–611, 1980.
4. Arnold, F.: Atmospheric Aerosol and Cloud Condensation Nuclei Formation: A Possible Influence of Cosmic Rays?, Space Sci. Rev., 125, 169–186, \\doi10.1007/s11214-006-9055-4, 2006.
5. Ball, S M., Hanson, D R., Eisele, F L., and McMurry, P H.: Laboratory studies of particle nucleation: Initial results for \\chemH_2SO_4, H_2O, and \\chemNH_3 vapors, J. Geophys. Res., 104, 23 709–23 718, \\doi10.1029/1999JD900411, 1999.