https://www.eppgroup.eu/download/file/t5F7fWVHAho9XFLF3fGb3HMHOc_fBpiq-JJIhg_2alGxibc6qNgf4Xn7KKgAAAACEQU0OTEyMw
http://www.ips-journal.eu/regions/europe/article/show/myth-of-the-echo-chamber-2135/
https://www.esri.ie/system/files/publications/QEC2022WIN_0.pdf