Luminescence Properties of Eu<sup>3⊕</sup> and Tb<sup>3⊕</sup> Complexes of Branched Macrocyclic Ligands Containing Four 2,2′‐Bipyridine UnitsVincenzo Balzani, Raymond Ziessel, J. van de Loosdrecht et al.|Angewandte Chemie International Edition in English|1991Cited by 64