https://www.kommersant.ru/doc/4759727
https://www.rosbalt.ru/world/2021/04/02/1895150.html
https://www.eurointegration.com.ua/news/2021/04/2/7121670/
https://foreignpolicy.com/2021/04/01/russia-ukraine-conflict-security-blinken-biden/
https://www.cnbc.com/2021/04/01/russia-and-ukraine-tensions-grow-again-on-the-border.html
https://ru.krymr.com/a/v-krymu-uzhestochayut-trebovaniya-k-piketam-i-mitingam/31182336.html
https://www.inopressa.ru/article/01Apr2021/wsj/russiatroups.html