Herráez, M., and J. Suñé. “Contribution to the Physical Study of the Tablets: Hardness Tests. Tablets from the National Pharmaceutical Market”. Ars Pharmaceutica (Internet), vol. 8, no. 7-10, June 1967, pp. 335-60, https://revistaseug.ugr.es/index.php/ars/article/view/7676.