โสมภีร์ ป., and คำวงศ์ ว. “Appropriate Harvesting Stage of Long Pepper (Piper retrofractum Vahl) to achieve Thai Herbal Phamacopeia”. Thai Agricultural Research Journal, vol. 33, no. 2, Feb. 2023, pp. 132-43, https://li01.tci-thaijo.org/index.php/thaiagriculturalresearch/article/view/77741.