Bản ghi email: Heptaaqua­(3,4,5,6-tetra­chloro­phthalato-κO (1))erbium(III) 2-carb­oxy-3,4,5,6-tetra­chloro­benzoate–3,4,5,6-tetra­chloro­phthalic acid–water (1/1/1)