Austerity measures in crisis countries - results and impact on mid-term development.
Vassilis Monastiriotis, Niamh Hardiman, Aidan Regan, Chiara Goretti, Lucio Landi, J. Ignacio Conde-Ruiz, Carmen Marín, Ricardo Cabral
Intereconomics/Review of European Economic Policy, vol. 48, 2013, p. 4-32.

Estimating Marginal Returns to Education
Pedro Carneiro, James Heckman, Edward Vytlacil
American Economic Review, vol. 101, 2011, p. 2754-2781.

EU Enlargement and the Portuguese Economy
Nuno Crespo, Maria Paula Fontoura, Frank Barry
World Economy, vol. 27, 2004, p. 781-802.