F. Sgambato, S. Prozzo, E. Sgambato, R. Sgambato, and L. Milano, “The 100th anniversary of the invention of pH (1909-2009) - Part II. Was it really necessary to replace the Henderson equation with that of Henderson-Hasselbalch?”, Ital J Med, vol. 5, no. 4, pp. 215–226, Jan. 2012.