9KATHARINE WAKELIN.Productivity growth and R&D expenditure in UK manufacturing firms[J].Research Policy,2001(30):1038-1087.
10DOMINIQUE GUELLEC,VAN POTTELSBERGHE DE LA POTTERIE.From R&D to productivity growth:do the institutional settings and the source of funds of R&D matter?[J].Oxford Bulletin of Economics & Statistics,2004(66):342-356.