https://science.sciencemag.org/content/early/2020/07/22/science.abd2438?rss=1
https://www.europarl.europa.eu/at-your-service/files/be-heard/eurobarometer/2019/parlemeter-2019/executive-summary/en-parlemeter-2019-executive-summary.pdf
http://ftp.iza.org/dp9466.pdf
https://www.icij.org/investigations/china-targets/china-transnational-repression-dissent-around-world/