MERDAN, HULYA, et al. “Extraction of Total Dyestuff from Centaury (Hypericum Scabrum L.) and Dyeing of Natural Fibres under Different Conditions”. Asian Journal of Chemistry, vol. 20, no. 1, Mar. 2010, pp. 608-14, https://asianpubs.org/index.php/ajchem/article/view/19466.