Biswas, R. K., et al. “Extraction Equilibrium of Ni(II) in the Ni<sup>2+< sup>-SO<sub>4< sub><sup>2-< sup>-Ac<sup>-< sup>(Na<sup>+< sup>, H<sup>+< sup>) - Cyanex 272 (H<sub>2< sub>A<sub>2< sub>)-Kerosene-3%(v V) Octan-1-Ol System”. Journal of Scientific Research, vol. 4, no. 1, Dec. 2011, p. 83, doi:10.3329/jsr.v4i1.8007.