VANKOV, D. Status, Trends and Problems of the Road Safety Field in Bulgaria. Periodica Polytechnica Transportation Engineering, [S. l.], v. 43, n. 1, p. 9–14, 2015. 10.3311/PPtr.7570. Disponível em: https://pp.bme.hu/tr/article/view/7570. Acesso em: 18 aug. 2022.