A. Preechaworapun, P. Lertsuwunpisal, and T. Tangkuaram, “Differential pulse anodic stripping voltammetry for Lead(II) Cadmium(II) and Zinc(II) analysison a low cost pencil carbon electrode”, Interdiscip. Res. Rev., vol. 11, no. 4, pp. 1–7, Oct. 2016.