Frank Rich (of the NYTimes, although he's moving to NY Mag) has always been great about linking to sources. Not always necessarily a primary source, but for an

Frank Rich (of the NYTimes, although he's moving to NY Mag) has always been great about linking to sources. Not always necessarily a primary source, but for an op-ed writer it makes a huge difference to show that you can back up your claims. Or at least that your sources think they can