The Shenzhen effect: Why China's original 'model' city matters more than ever
https://edition.cnn.com/style/article/shenzhen-effect-china-model-city-intl-hnk/index.html
Though the article says there is no space to expand, there is still much space inland like Huizhou City. I wonder why they are reluctant to expand its urban area. On the other hand, in Japan, suburban city of Tokyo expands to farther than 70km away from downtown. Only if there is a rapid transportation, it won't be inconvenient to build a new city in farther place.
