1. An J S, 2004. Study on some laws of migration in ancient China. Geographical Research, 23(5): 667–676. (in Chinese)
2. Bao C, 2014. Spatiotemporal coupling relationships among urbanization, economic growth and water use change in China. Acta Geographica Sinica, 69(12): 1799–1809. (in Chinese)
3. British Media Forecast (BMF), 2014. China beyond American economy in 2021. Reference News, 08-25(3).
4. Cai F, 2007. China Population and Sustainable Development. Beijing: Science Press. (in Chinese)
5. Cao G Z, Liu T, 2011. Rising role of inland regions in China’s urbanization in the 21st century: The new trend and its explanation. Acta Geographica Sinica, 66(12): 1631–1643. (in Chinese)