W. Srimaharaj, S. Chaising, P. Temdee, P. Sittiprapaporn, and R. Chaisricharoen, “Identification of L-Theanine Acid Effectiveness in Oolong Tea on Human Brain Memorization and Meditation”, ECTI-CIT Transactions, vol. 13, no. 2, pp. 129–136, Jan. 2020.