“Zn(II) PRECONCENTRATED WITH CATION EXCHANGER PS-DVB-SO3H WITH PH CONTROL AND ELUID RECOVERY ANALYSIS WITH ATOMIC ABSORPTION (EAAF)”. 2012. Revista Peruana De Química E Ingeniería Química 15 (1): 15-20. https://revistasinvestigacion.unmsm.edu.pe/index.php/quim/article/view/4753.