"大阪市営地下鉄が公営初の民営化、18年４月 市議会が可決" [Osaka Municipal Subway becomes the first public privatization, passed by the city council in April 2018]. Nihon Keizai Shimbun Online (in Japanese). 28 March 2017. Archived from the original on 12 August 2018. Retrieved 20 June 2022.
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"大阪市営地下鉄が公営初の民営化、18年４月 市議会が可決" [Osaka Municipal Subway becomes the first public privatization, passed by the city council in April 2018]. Nihon Keizai Shimbun Online (in Japanese). 28 March 2017. Archived from the original on 12 August 2018. Retrieved 20 June 2022.
