Cahyana, Ucu, et al. “SYNTHESIS OF 1,9-BIS [1-PHENYL-3-METHYL-5-HYDROXY-4-PYRAZOLYL] 1,9 NONANEDIONE AND ITS APPLICATION FOR THE EXTRACTION OF COBALT ( II), NICKEL (II), AND CADMIUM (II)”. JRSKT - Jurnal Riset Sains Dan Kimia Terapan, vol. 2, no. 2, Mar. 2017, pp. 200-6, doi:10.21009/JRSKT.022.08.