<i>catena</i>-Poly[[[tetrakis(μ-2-butenoato)dicopper(II)]-μ-2-butenoato-[diaqua(2-butenoato)holmium(III)]-di-μ-2-butenoato-[diaqua(2-butenoato)holmium(III)]-μ-2-butenoato] trihydrate]
Acta crystallographica. Section E