Šauer, Martin, Vilém Pařil, and Milan Viturka. “Integrative Potential of Central European Metropolises With a Special Focus on the Visegrad Countries”. Technological and Economic Development of Economy 25, no. 2 (February 14, 2019): 219-238. Accessed January 21, 2022. https://journals.vgtu.lt/index.php/TEDE/article/view/7555.