Analysis of information sources in references of the Wikipedia article "Katowice urban area" in English language version.
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: CS1 maint: ignored ISBN errors (link)Katowice conurbation, together with the agglomerations of Kraków, Rybnik, Bielsko-Biała and Częstochowa and the agglomeration of Ostrava in the Czech Republic, make up an interstate agglomeration zone
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