Lars Molteberg Glomnes (25 March 2014). "Stoltenberg med hard Russland-kritikk" [Stoltenberg was met with fierce criticism from Russia]. Aftenposten (in Norwegian). Archived from the original on 29 March 2014.
Guinness World Records: First murder by radiation: On 23 November 2006, Lieutenant Colonel Alexander Litvinenko, a retired member of the Russian security services (FSB), died from radiation poisoning in London, UK, becoming the first known victim of lethal Polonium 210-induced acute radiation syndrome.
RAND, Russia's Hostile Measures: Combating Russian Gray Zone Aggression Against NATO in the Contact, Blunt, and Surge Layers of Competition (2020) online
В квартире Немцова проводится обыск [A search is going on in Nemtsov's flat] (in Russian). Russia: RBK. 28 February 2015. Archived from the original on 2 March 2015. Retrieved 28 February 2015.
Lars Molteberg Glomnes (25 March 2014). "Stoltenberg med hard Russland-kritikk" [Stoltenberg was met with fierce criticism from Russia]. Aftenposten (in Norwegian). Archived from the original on 29 March 2014.
The State of the World's Human Rights (Internet Archive), Amnesty International 2009, Report on Jan–Dec 2008, p. 272: "In June [2008], the Office of the Prosecutor General announced that it had finished its investigation into the killing of human rights journalist Anna Politkovskaya, who was shot dead in Moscow in October 2006. Three men accused of involvement in her murder went on trial in November; all denied the charges. A fourth detainee, a former member of the Federal Security Services who had initially been detained in connection with the murder, remained in detention on suspicion of another crime. The person suspected of shooting Anna Politkovskaya had not been detained by the end of the year and was believed to be in hiding abroad."
В квартире Немцова проводится обыск [A search is going on in Nemtsov's flat] (in Russian). Russia: RBK. 28 February 2015. Archived from the original on 2 March 2015. Retrieved 28 February 2015.