Sivakumar, R., R. Jayaprakasam, V. Renuga, and C. Sasikumar. 2010. “Investigation on Eco-Friendly Natural Dyes: Chemistry, Dyeing and Antimicrobial Properties of Helichrysum Bracteatum”. Asian Journal of Chemistry 21 (8):5960-66. https://asianpubs.org/index.php/ajchem/article/view/12276.