MÂNZATU, Carmen, et al. “THE USE OF CHEMICALLY ACTIVATED FIR CONE CARBON IN THE REMOVAL OF Pb²⁺ CONTAMINATED AQUEOUS SOLUTIONS”. Studia Universitatis Babeș-Bolyai Chemia, vol. 61, no. 3, Sept. 2016, pp. 167-82, https://studia.reviste.ubbcluj.ro/index.php/chemia/article/view/8342.