Reuse of Newspaper As An Adsorbent For Cu (II) Removal By Citric Acid ModificationMardiah, Rif’an Fathoni, Pratiwi Pudyaningtyas, Hamdania Gamu and RinaldyMATEC Web Conf., 156 (2018) 02012DOI: https://doi.org/10.1051/matecconf/201815602012