Hu, Gang, et al. “B-Z Oscillating Reactions Catalyzed by a Tetraazamacrocyclic Nickel(II) Complex in the Pyruvic Acid-Sulfuric Acid System”. Asian Journal of Chemistry, vol. 12, no. 4, Mar. 2010, pp. 1031-6, https://asianpubs.org/index.php/ajchem/article/view/23125.