1. R.G. Pearson Chemical Hardness - An Historical Introduction 2. P.K. Chattaraj Density Functional Theory of Chemical Hardness 3. J.L. Gazqu z Hardness and Softness in Density Functional Theory 4. L. Komorowski Hardness Indices for Free and Bonded Atoms 5. N.H. March The Ground-State Energy of Atomic and Molecular Ions and Its Variation with the Number of Elections 6. K. Sen Isoelectronic Changes in energy, Electronegativity, and Hardness in Atoms via the Calculations of 7. P. Politzer, J.S. Murray, M.E. Grice Charge Capacities and Shell Structures of Atoms 8. R. F. Nalewajski The Hardness Based Molecular Charge Sensitivities and Their Use in the Theory of Chemical Reactivity 9. B.G. Baekelandt, R. A. Schoonheydt, W.J. Mortier The EEM Approach to Chemical Hardness in Molecules and Solids: Fundamentals and Applications 10. J.A. Alonso, L. C. Balbas Hardness of Metallic Clusters