Tastan, Serkan, and Halil Ozekicioglu. “Development of European Union and China Bilateral Trade After The 2008 Financial Crisis: A Cluster Analysis”. International Journal of Economics and Financial Issues, vol. 4, no. 2, Mar. 2014, pp. 336-43, https://econjournals.com.tr/index.php/ijefi/article/view/756.