CREATE TABLE table_56840 ("CERCLIS ID" CLOB, "Name" CLOB, "County" CLOB, "Proposed" CLOB, "Listed" CLOB, "Construction completed" CLOB, "Partially deleted" CLOB, "Deleted" CLOB)

What construction has a Listed 09/08/1983, and a Deleted of , and a Name of mid-south wood products?
SELECT "Construction completed" FROM table_56840 WHERE "Listed" = '09/08/1983' AND "Deleted" = '–' AND "Name" = 'mid-south wood products'
SELECT "Construction completed" FROM "table_56840" WHERE "Deleted" = '–' AND "Listed" = '09/08/1983' AND "Name" = 'mid-south wood products'