“Removal of Chromium, Iron and Manganese from Contaminated Waters Using Cryogels As Adsorbent”. Revista Torreón Universitario 10, no. 27 (February 4, 2021): 130–139. Accessed August 9, 2025. https://revistas.unan.edu.ni/index.php/Torreon/article/view/3140.