Afdhol, Muhammad Khairul, Hafni Zulaika Lubis, and Chalidah Pratiwi Siregar. 2019. “Bioethanol Production from Tea Waste As a Basic Ingredient in Renewable Energy Sources”. Journal of Earth Energy Engineering 8 (1):21-26. https://doi.org/10.25299/jeee.2019.vol8(1).2602.