F. Halbus, Ahmed, and Falah H. Hussein. “Heterogeneous Photocatalytic Decolourization of Cobalamine in the Presence of Aqueous Titanium Dioxide Suspensions”. Asian Journal of Chemistry, vol. 24, no. 12, Aug. 2012, pp. 5579-81, https://asianpubs.org/index.php/ajchem/article/view/9937.