PAŠAGIĆ, Senka; ŠČUKANAC, Anđelko. Historical Development of Traffic Signs. Promet - Traffic&Transportation, [S. l.], v. 10, n. 5-6, p. 309–313, 2012. Disponível em: https://traffic2.fpz.hr/index.php/PROMTT/article/view/1887. Acesso em: 26 aug. 2025.