VARGA, A.; PONTIKAKIS, D.; CHOROAFAKIS, G. Agglomeration and interregional network effects on European R&D productivity. PTE KTK Műhelytanulmányok, [S. l.], v. 2010, n. 1-4, 2022. Disponível em: https://journals.lib.pte.hu/index.php/workingpapers/article/view/5932. Acesso em: 4 máj. 2024.