[Koha] Need to deleter Duplicate Records with no items

When we did our data entry with Koha and ended up  having a bunch of duplicate records with no items.  We discovered that using Internet Explorer instead of Foxfire as our browser. Based on posts on the Koha list I am assuming it  caused the problem.  Unfortunately, we didn't figure out this fact until we'd done several thousand entries.  We're now trying to clean up our records. What is the right SQL query is to find those records for deletion ?  The only table we've  found with the barcodes didn't show the items with blank barcodes.  Any suggestions? Thanks so much, Janet Deavor St. John Catholic School North Chareston, Sc