Ruengsitagoon, Wirat, and Chantana Aromdee. “Determination of lead, copper, zinc and iron in centella asiatica by atomic absorption spectrophotometry (Thai)”. Asia-Pacific Journal of Science and Technology 14, no. 5 (April 19, 2017): 412–420. accessed April 22, 2026. https://so01.tci-thaijo.org/index.php/APST/article/view/83452.