Moon, Dohyun, et al. “Synthesis, Crystal Structure and Hirshfeld Surface Analysis of 3,14-Dimethyl-2,6,13,17-tetraazatricyclo(16.4.0.07,12)docosane-2-(nitric Acid)”. Asian Journal of Chemistry, vol. 32, no. 3, Jan. 2020, pp. 697-02, doi:10.14233/ajchem.2020.22506.