Friedery, Réka. “Hardening Borders During the Pandemic in the European Union: The Shape of the Schengen Borders Code and the EU Digital COVID Certificate”. Quarterly on Refugee Problems - AWR Bulletin 61, no. 1 (September 20, 2022): 71–84. Accessed April 29, 2024. https://ejournals.bibliothek.thws.de/qrp/article/view/29.