Partially returned Orders

SELECT order_number , ordered_date , ordLines , returnLines FROM (SELECT /*+ cardinality (oeH 1) */ oeH.order_number , oeh.Ordered_date , count(distinct oeL.line_id) ordLines , count(distinct oeLR.line_id) returnLines FROM apps.oe_order_headers_all oeH , apps.oe_order_lines_all oeL , apps.oe_order_lines_all oeLR WHERE oeH.ordered_date BETWEEN SYSDATE - 50 AND SYSDATE - 49.75 AND oeH.header_id = oeL.header_id AND oeL.line_id = oeLR.reference_line_id (+) GROUP BY oeH.order_number , ordered_date HAVING COUNT(*) > 1 ) a WHERE ordLines > returnLines AND returnLines > 0;