1. My personal relation to George Olah last 44 years and goes back to 1974 and details are published,1997
2. Nonclassical Ions;Bartlett,1965
3. Carbonium Ions;Wiberg,1972
4. The Nonclassical Ion Problem;Brown,1977
5. The 2-norbornyl cation revisited;Brown;Acc Chem Res,1986