Assessing the Nonlinear Nature of the Effects of R&D Intensity on Growth of SMEs: A Dynamic Panel Data Approach
Paulo Maçãs Nunes, Zélia Serrasqueiro, João Leitão
Journal Of Evolutionary Economics, vol. 23, 2013, p. 97-128.

Is There a Linear Relationship between R&D Intensity and Growth? Empirical Evidence of Non-High-Tech vs. High-Tech SMEs
Paulo Maçãs Nunes, Zélia Serrasqueiro, João Leitão
Research Policy, vol. 41, 2012, p. 36-53.

Are There Non-linearities between SME Growth and Its Determinants? A Quantile Approach
Zélia Serrasqueiro, Paulo Maçãs Nunes, João Leitão, Manuel Rocha Armada
Industrial And Corporate Change, vol. 19, 2010, p. 1071-1108.