If you don't have it yet, Ed Engel's book on white doo wop groups appears again on ebay.
Another great opportunity to get this book with great photos and biographies.
Click here; https://www.ebay.com/itm/303971034224?mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338722076&toolid=10001