<i>catena</i>-Poly[[tetrakis(hexamethylphosphoramide-κ<i>O</i>)bis(nitrato-κ<sup>2</sup><i>O</i>,<i>O</i>′)erbium(III)] [silver(I)-di-μ-sulfido-tungstate(VI)-di-μ-sulfido]]
Acta crystallographica. Section E