A. Nekrep, S. Strašek, in D. Boršič, „Productivity and Economic Growth in the European Union: Impact of Investment in Research and Development“, OE, let. 64, št. 1, str. 18–27, jul. 2018, Pridobljeno: jul. 21, 2026. Dostopno na: https://journals.um.si/index.php/oe/article/view/2189