Nfor, Emmanuel Ngwang, et al. “Synthesis, Structure and Hydrogen Sorption Properties of a Pyrazine-Bridged copper(I) Nitrate Metal-Organic Framework”. European Journal of Chemistry, vol. 10, no. 3, Sept. 2019, pp. 195-00, doi:10.5155/eurjchem.10.3.195-200.1888.