
https://www.science.org/content/article/cutting-cartel-recruitment-could-be-only-way-reduce-mexico-s-violence

http://www.ips-journal.eu/regions/global/article/show/why-pollsters-normally-get-it-right-more-or-less-2299/

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/635900/2017-08-07_DP_Bill_-_Statement_of_Intent.pdf