Techau, Jan (2. 9. 2015). „The Politics of 2 Percent: NATO and the Security Vacuum in Europe”. Carnegie Europe. Приступљено 11. 7. 2018. „A month before [the alliance’s summit in Riga in 2006], Victoria Nuland, then the U.S. ambassador to NATO, called the 2 percent metric the “unofficial floor” on defense spending in NATO. But never had all governments of NATO’s 28 nations officially embraced it at the highest possible political level – a summit declaration.”
„Operation OCEAN SHIELD”. mc.nato.int (на језику: енглески). Allied Maritime Command. Архивирано из оригинала 15. 05. 2019. г. Приступљено 7. 9. 2019.
nytimes.com
Erlanger, Steven (26. 3. 2014). „Europe Begins to Rethink Cuts to Military Spending”. nytimes.com. Приступљено 3. 4. 2014. „Last year, only a handful of NATO countries met the target, according to NATO figures, including the United States, at 4.1 percent, and Britain, at 2.4 percent.”