http://www.rbc.ru/newspaper/2017/04/24/58fa30dc9a7947dfe79642b6
http://ru.krymr.com/a/28444993.html
https://www.gazeta.ru/comments/2017/04/21_a_10637945.shtml
https://www.gazeta.ru/army/2017/04/22/10639757.shtml
http://www.kommersant.ru/doc/3280152
http://www.kommersant.ru/doc/3280141
Russian Planes Buzz Alaska Four Nights in a Row « | Foreign Policy | the Global Magazine of News and Ideas
http://foreignpolicy.com/2017/04/21/russian-planes-buzz-alaska-four-nights-in-a-row/
http://www.rbc.ru/newspaper/2017/04/21/58f8afd19a79470f77cc6604
http://expert.ru/2017/04/21/benzin/