N. Kotsev, “The Impact of the Promotion of Innovations on the Establishing of Industrial Concentrations (Clusters) in the Information Technology Sector in Bulgaria”, НТ, no. 2, pp. 112–139, Aug. 2014, Accessed: Jul. 23, 2026. Available: https://yb.e-dnrs.org/index.php/rp/article/view/5686