Kelar, K., et al. “Polyamide 6 Modified With Silsesquioxane Prepared via Anionic Polymerization of E-Caprolactam”. Polimery, vol. 57, no. 10, Oct. 2012, pp. 697-04, https://polimery.ichp.vot.pl/index.php/p/article/view/865.