HÉLÈNE SYED ZWICK AND S. ALI SHAH SYED. The EU Blue Card scheme: A polarization vector. European Economic Letters (EEL), [S. l.], v. 4, n. 1, p. 30–36, 2022. DOI: 10.52783/eel.v4i1.38. Disponível em: https://eelet.org.uk/index.php/journal/article/view/38. Acesso em: 22 oct. 2025.