Pimsiri, K., Y. Punsri, J. Pusri, V. Kumpanawarawan, B. Noppon, A. Chatchawanchonteera, and N. Trakranrungsie. “An In Vitro Testing of Ethanol Extract of Piper Betle Leave Against Campylobacter Jejuni”. Journal of Basic and Applied Pharmacology, vol. 27, no. 1, July 2015, p. 48, https://li01.tci-thaijo.org/index.php/JBAP/article/view/37254.