1. Younge, Gary . 2008. “The Invisible Poor.” The Guardian (online). January 23, 2008.218
2. Issue Attention and Legislative Proposals in the U.S. Senate
3. Wolbrecht, Christina . “American Political Party Platforms: 1948–2008.” Policy Agendas Project at the University of Texas at Austin. 2017. www.comparativeagendas.net.