1. Alicia H. Munnell, Anthony Webb, Luke Delorme, y Francesca Golub-Saas, «National Retirement Risk Index: How Much Longer Do We Need to Work?», Center for Retirement Research Report, nº 12-12 (junio de 2012); Teresa Ghilarducci, «Our Ridiculous Approach to Retirement», New York Times, 21 de Julio de 2012.