Vivas-Reyes, R., & Arias, A. (2008). Evaluation of group electronegativities and hardness (softness) of group 14 elements and containing functional groups through density functional theory and correlation with NMR spectra data. Eclética Química, 33(3), 69–76. https://doi.org/10.26850/1678-4618eqj.v33.3.2008.p69-76