da Costa, A. C. A., F. do N. Corrêa, and G. de S. Sant’anna. “A Timeline of Analytical Techniques for Characterization and Treatment of Iron-Gall Ink – A Brief Overview of the Last Two Decades”. American Scientific Research Journal for Engineering, Technology, and Sciences, vol. 31, no. 1, May 2017, pp. 249-64, https://asrjetsjournal.org/index.php/American_Scientific_Journal/article/view/2931.