Google's WT index seems to provide a fair amount of the links. There are a few 3rd party tools that do a really good job of indexing nearly all of the backlinks

Google's WT index seems to provide a fair amount of the links. There are a few 3rd party tools that do a really good job of indexing nearly all of the backlinks to your site: http://www.opensiteexplorer.org http://www.opensiteexplorer.org http://www.ahrefs.com http://www.ahrefs.com http://www.majesticseo.com http://www.majesticseo.com