1. Hard and soft acids and bases;Pearson;J. Am. Chem. Soc.,1965
2. General features of homogeneous catalysis with transition metals;Ugo;Chim. Ind. (Milan),1969
3. Chemical softness and specific adsorption at electrodes;Barclay;J. Electroanal. Chem.,1968
4. “Hard and soft Acids and Bases Principle in Organic Chemistry”;Ho,1977
5. Acids and bases;Pearson;Science,1966