Sopajarn, Arrisa, Suhdee Niseng, Teerayut toyarn, and Teerapat Ritplin. 2020. “Investigation of Piper Betle Herbal Tea Drying With Infrared Heater by Solar Cell Power”. Rajamangala University of Technology Srivijaya Research Journal 12 (1):171-79. https://li01.tci-thaijo.org/index.php/rmutsvrj/article/view/242050.