Sakloetsakun, D., and A. B. Schnürch. “Effect of aliphatic and aromatic thiolated chitosan conjugates on permeability of ritonavir across caco-2 cell monolayers and rat intestinal membrane”. Asia-Pacific Journal of Science and Technology, vol. 17, no. 3, Apr. 2017, pp. 469-7, https://so01.tci-thaijo.org/index.php/APST/article/view/83260.