12.01.17 Financial Times UK
por Jo Bail
1. 01.01.17 The Guardian
1.1. 31.12.16 Der Spegel
1.1.1. Named Government Source
1.2. Reporter David Crouch
2. Date Unknown Unnamed Security Expert
3. 12.05.17 Russia Today
3.1. 12.04.16 Berosvki News
3.1.1. Date unknown. Unnamed Security