Innovation Economy, Productive Public Expenditure and Economic Growth
Óscar Afonso, Sara Monteiro, Maria Thompson
Metroeconomica, vol. 65, 2014, p. 671-689.

A growth model for the quadruple helix
Óscar Afonso, Sara Monteiro, Maria Thompson
Journal of Business Economics and Management, vol. 13, 2012, p. 849-865.