https://nv.ua/opinion/fesenko/mn17-i-rossija-kak-dejstvovat-ukraine-2471998.html
The crash of a Polish Air Force Tu-154 airliner near the Russian city of Smolensk on April 10, 2010 killed Polish President Lech Kaczyński and his wife.
http://observer.com/2018/05/evidence-shows-russia-had-role-in-smolensk-crash-killed-kaczynski/
https://day.kyiv.ua/ru/blog/politika/smolenskaya-katastrofa-rassledovanie-prodolzhaetsya
http://www.kasparov.ru/material.php?id=5AE43498C0756
https://republic.ru/posts/90538
https://www.svoboda.org/a/29170644.html
https://www.svoboda.org/a/29159545.html
https://focus.ua/opinions/395413/