Exclusive: Largest Dark Money Donor Groups Share Funds, Hide Links | Common Dreams News
https://www.commondreams.org/news/2013/09/11/exclusive-largest-dark-money-donor-groups-share-funds-hide-links
Koch Group's IRS Report Unlocks A Few Mysteries - OpenSecrets News
https://www.opensecrets.org/news/2013/09/koch-groups-irs-report-unlocks-mysteries-details-giant-trade-group/