Impact of covid-19 on European and Turkey air traffic networks. Revista de Investigaciones Universidad del Quindío, [S. l.], v. 33, n. 2, p. 45–55, 2021. DOI: 10.33975/riuq.vol33n2.603. Disponível em: https://ojs.uniquindio.edu.co/ojs/index.php/riuq/article/view/603. Acesso em: 25 jun. 2026.