"Synthesis and Characterization of Novel Tetradentate Macrocycle Ligand Type N4 (1,5,8,12 - tetraazacyclotetradecan – 6,7,13,14 -tetraone)and its Complexes with Co(II), Ni(II), Cu(II) and Zn(II)", DJHR, م 1, عدد 39, 2022, doi: 10.57592/djhr.v1i39.2182.