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

Chemical hardness - A historical introduction

Density functional theory of chemical hardness
Hardness and softness in density functional theory
Hardness indices for free and bonded atoms
The ground-state energy of atomic and molecular ions and its variation with the number of electrons
Isoelectronic changes in energy, electronegativity, and hardness in atoms via the calculations of TANO
Charge capacities and shell structures of atoms
The hardness based molecular charge sensitivities and their use in the theory of chemical reactivity
The EEM approach to chemical hardness in molecules and solids: Fundamentals and applications
Hardness of metallic clusters.