https://www.svoboda.org/a/31467728.html
https://jamestown.org/program/the-russian-elections-and-hidden-regionalist-politics/
http://region.expert/no-parties/
http://region.expert/spb-taxes/
http://www.kasparov.ru/material.php?id=61389BE0D3378
https://newtimes.ru/articles/detail/205122?fcc