1. AFP.2013. Turkey violence flares after police storm protest park. Accessed May 11 2016.https://fr.news.yahoo.com/video/turkey-violence-flares-police-storm-191500809.html.
2. Lowery W.2014. Police use tear gas on crowd in Ferguson Mo. protesting teen's death. Accessed May 20 2016.http://www.washingtonpost.com/news/post-nation/wp/2014/08/12/police-use-tear-gas-on-crowd/.
3. Pomfret J.&Y.Lee.2014. Hong Kong democracy protesters defy tear gas baton charge in historic standoff. Accessed May 12 2016.http://www.reuters.com/article/us-hongkong-china-idUSKCN0HN03Q20140928.
4. Edmonds L.2013. Greece rocked by night of riots after anti‐fascist rapper was stabbed to death by member of far‐right group Golden Dawn. Accessed May 12 2016.http://www.dailymail.co.uk/news/article-2424967/Pavlos-Fyssas-murder-Golden-Dawn-sparks-Greece-riots.html.
5. Romero S.2013. Thousands gather for protests in Brazil's largest cities. Accessed May 20 2016.http://www.nytimes.com/2013/06/18/world/americas/thousands-gather-for-protests-in-brazils-largest-cities.html.