Riedo, Theodor J., and Thomas A. Kaden. “Complexes With Macrocyclic Ligands, VIII. Stability of the Cu(II) Complexes With 1,4,7-Triazacyclodecane and 1,5,9-Triazacyclododecane”. CHIMIA, vol. 31, no. 6, June 1977, p. 220, https://doi.org/10.2533/chimia.1977.220.