Analysis of Caffeine and Heavy Metal Contents in Branded and Unbranded Tea Available in Pakistan: Caffeine and Heavy Metals in Tea. Biological Sciences - PJSIR, [S. l.], v. 53, n. 1, p. 20–24, 2010. Disponível em: https://biostaging.pjsir.org/index.php/biological-sciences/article/view/414. Acesso em: 21 mar. 2026.