U. Cahyana, B. Rusdiarso, and N. Narsito, “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, vol. 2, no. 2, pp. 200 - 206, Mar. 2017.