Source Data Reference for:

City = Xian
Time = 600

City	Year	Size	Size Comment	Year Comment	Author	Title	Location
Changan	500	100,000			George Modelski	World Cities -3000 to 2000	p44
Changan	500	95,000	"btw 90,000 & 100,000"		Tertius Chandler	Four thousand years of urban growth	p465
Changan	600	400,000			George Modelski	World Cities -3000 to 2000	p44
Changan	622	400,000			Tertius Chandler	Four thousand years of urban growth	p537
Changan	622	400,000			Tertius Chandler	Four thousand years of urban growth	p466
Changan	622	400,000			Tertius Chandler	Four thousand years of urban growth	p532
Changan	622	400,000			Tertius Chandler	Four thousand years of urban growth	p531
Changan	622	400,000			Tertius Chandler	Four thousand years of urban growth	p522
Changan	637		becomes largest in the world overtaking Ctesiphon		Tertius Chandler	Four thousand years of urban growth	p527