中国七大中心城市人口资源大调查 23 Eylül 2015 tarihinde Wayback Machine sitesinde arşivlendi."Population survey of the seven central cities of China", Zhang Zhizhong, National Family Planning Commission
中国七大中心城市人口资源大调查 23 Eylül 2015 tarihinde Wayback Machine sitesinde arşivlendi."Population survey of the seven central cities of China", Zhang Zhizhong, National Family Planning Commission