1. Mechanical hardness: A semiempirical theory based on screened electrostatics and elastic shear
2. Mechanical hardness and elastic stiffness of alloys: semiempirical models
3. G. Simmons, H. Wang, Single Crystal Elastic Constants and Calculated Aggregate Properties: A Handbook, MIT Press, Cambridge, MA, 1971. Page references: diamond, p. 186; TiB2, p. 325.
4. T.J. Clark, R.C. DeVries, Superabrasives and ultrahard tool materials, in: Metals Handbook, vol. 2, 10th ed., Properties and Selection: Nonferrous Alloys and Special-Purpose Alloys, ASM International, Materials Park, OH, 1990, pp. 1008–1018. The measured hardness of diamond was obtained by averaging 7000–10 000HK, and then multiplying by 0.0098.
5. M. Grimsditch, E.S. Zouboulis, A. Polian, J. Appl. Phys. 76(2) (1994) 832. β-BN bulk and shear moduli are arithmetic averages of Hashin–Shtrikman values calculated using values of c11, c12 and c44 that appear in this reference.