Should Portuguese Economy Invest in Defense Spending? A Revisit
Muhammad Shahbaz, Nuno Carlos Leitão, Gazi Salah Uddin, Mohamed Arouri, Frédéric Teulon
Economic Modelling, vol. 35, 2013, p. 805-815.

Foreign Direct Investment-Economic Growth Nexus: The Role of Domestic Financial Development in Portugal
Muhammad Shahbaz, Nuno Carlos Leitão, Summaira Malik
Economics Bulletin, vol. 31, 2011, p. 2824-2838.