Един все по-диференциран Европейски съюз

Benes, V., & Braun, M. (2013). An ever-closer eurozone and its consequences for differentiated integration in Europe. In S. Blockmans (Ed.), Differentiated Integration in the EU: From the Inside looking out. CEPS.

Delors, J., Vitorino, A., Lamy, P., & Bertoncini, Y. (2013). European Elections: Full Steam Ahead (Tribune). Notre Europe – Jacques Delors Institute.

Dyson, K., & Sepos, A. (Eds.). (2010). Which Europe? The Politics of Differentiated Integration. Palgrave Studies in European Union Politics.

Fon Ondarza, N. (2013, March). Strengthening the Core or Splitting Europe? Prospects and Pitfalls of a Strategy of Differentiated Integration (SWP Research Paper). Stiftung Wissenschaft und Politik German Institute for International and Security Affairs.

Kaczynski, P. (2011). Polish Council Presidency 2011: Ambitions and Limitations. Swedish Institute for European Policy Studies.

Ricard-Nihoul, G. (2012). Pour une Federation Europeenne d’Etats Nation, La vision de Jacques Delors revisitee. Larcier.

Schimmelfennig F. (2014). EU Enlargement and Differentiation: Discrimination or Equal Treatment? Journal of European Public Policy, 21(5).

Wallace, H. (1998). Differentiated Integration. In D. Dinan (Ed.), Encyclopedia of the European Union. Lynne Rienner Publishers.