Access 2003 query question

[easg]

I have this query that is duplicating values of the table [Detalle Compra], for each recorset of Sum(Nz([Cant_vendida],0)) it place a record of Sum(Nz([Cantidad_Ent],0)) for example if I have only one entry of 6 and three outs of one, two and three it does this

Entries outs

6 1
6 2
6 3


SELECT [Detalle compra].ID_Producto, [Catalogo de Articulos].Descripcion_Productos, Sum(Nz([Cantidad_Ent],0)) AS Entradas, Sum(Nz([Cant_vendida],0)) AS Salidas, Sum(Nz([Cantidad_Ent],0)-nz([Cant_vendida],0)) AS Existencia, [Tipos de Articulos].[Tipo de Articulo]
FROM [Tipos de Articulos] INNER JOIN (([Catalogo de Articulos] LEFT JOIN [Detalle compra] ON [Catalogo de Articulos].ID_Productos = [Detalle compra].ID_Producto) LEFT JOIN [Detalle Facturas] ON [Catalogo de Articulos].ID_Productos = [Detalle Facturas].ID_Articulo) ON [Tipos de Articulos].ID_Tipo_Art = [Catalogo de Articulos].Tipo_articulo
GROUP BY [Detalle compra].ID_Producto, [Catalogo de Articulos].Descripcion_Productos, [Tipos de Articulos].[Tipo de Articulo]
HAVING ((([Tipos de Articulos].[Tipo de Articulo])="Articulo"));



There is an attach with the image of the query desing