Romero Jordán (Universidad Rey Juan Carlos) D, Delgado Rodríguez (Universidad Rey Juan Carlos) MJ, Álvarez Ayuso (Universidad Autónoma de Madrid) I. R&D and productivity in the spanish´s manufacturing firms. ReE. 2010;(2). Accessed March 9, 2026. https://revistaselectronicas.ujaen.es/index.php/REE/article/view/352