06.04.2018
Source: "Murman" STRBC
22.07.2016
Source: Admiral Makarov State University of Maritime and Inland Shipping
11.05.2016
Source: "Russia 1" TV channel
29.04.2014
Source: "Rossiyskaya Gazeta" newspaper
07.02.2014
Source: "EnergyLand.info" Internet Portal of the Fuel and Energy Complex Society