T. J. Riedo and T. 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, p. 220, Jun. 1977, doi: 10.2533/chimia.1977.220.