Soroka, J. A., Z. Rosłaniec, and E. K. Wróblewska. “Solvatochromic Dyes in Polymers Structures Investigations. Part I. Diffusion Profiles in poly(butylene Terephthalate)”. Polimery, vol. 47, no. 11-12, Sept. 2022, pp. 828-32, https://ichp.vot.pl/index.php/p/article/view/2037.