A one-dimensional ladder-like coordination polymer: poly[[hexaaquabis(μ-5-nitrobenzene-1,3-dicarboxylato-κ<sup>3</sup><i>O</i>,<i>O</i>′,<i>O</i>′′)(μ-oxalato-κ<sup>4</sup><i>O</i>,<i>O</i>′:<i>O</i>′′,<i>O</i>′′′)diyttrium(III)] trihydrate]
Acta crystallographica. Section E