The 2 linked references in paper Rabah Arezki, Bertrand Candelon, Amadou Sy (2011) “Sovereign Rating News and Financial Markets Spillovers: Evidence from the European Debt Crisis” / RePEc:ces:ceswps:_3411

  1. Fama, E. (1970), “Efficient Capital Markets: A Review of Theory and Empirical Work.” Journal of Finance, 25, 383-417
  2. White, L. J. 2010. "Markets: The Credit Rating Agencies." Journal of Economic Perspectives, 24(2): 211–26.