Schengen: Controversial EU free movement deal explained - BBC News
6 Schengen Area Countries Have Now Extended Their Border Controls for Another Half-Year - SchengenVisaInfo.com
Strengthening the EU's external borders - Consilium
Border checks in EU challenge Schengen Agreement – DW – 11/12/2019
Eight Schengen Countries Keeping Internal Border Controls in Place - SchengenVisaInfo.com
List of non Schengen countries (= not part of the Schengen zone)
France Strategie: Schengen Area GDP Significantly Affected by EU Immigration Border Controls
The Future of Schengen – European Council on Foreign Relations
Europe's Schengen area: border free, with exceptions – European Data News Hub
The Schengen crisis: a failure - The New Federalist
Border checks in EU challenge Schengen Agreement – DW – 11/12/2019
Schengen Border Controls in the Time of Coronavirus (April 14, 2020) - Political Geography Now
Free movement and border policies in Africa and Europe
Border fences and internal border controls in Europe (March 2017) - World | ReliefWeb
Border checks in EU challenge Schengen Agreement – DW – 11/12/2019
6 Schengen Area Countries Still Keeping Temporary Internal Border Controls in Place - SchengenVisaInfo.com
Why the Schengen agreement might be under threat | The Economist
EU internal borders may be reimposed for two years
Is this the end of Schengen? | World Economic Forum
Schengen Area - Wikipedia
Schengen Area - Wikipedia
Entry/Exit System (EES) - Schengen Area Border Control
Europe had a dream of a land without borders. Now that dream may be turning to dust. - The Washington Post
Europe Rethinks the Schengen Agreement
Ever Closed Borders - Das Progressive Zentrum
