Noojaree Prasitpan, Supanna Tivakornpannarai, Amnard Tantivanich, Somneuk Pongumpai, and Pramuk Likitrammanit. “Survey of Alkaloids from Lagerstroemia”. Agriculture and Natural Resources, vol. 22, no. 3, Sept. 1988, pp. 207-12, https://li01.tci-thaijo.org/index.php/anres/article/view/242360.