Source Data Reference for:

City = Hannover
Time = 1850

City	Year	Size	Size Comment	Year Comment	Author	Title	Location
Hannover	1850	31,000			Paul Bairoch	La population des villes europeennes de 800 a 1850
Hannover	1850	47,000			Tertius Chandler	Four thousand years of urban growth	p26
Hannover	1861	71,200		1861/62	n/a	Gothaischer Hofkalender
Hannover	1874	100,000	passed for the 1st time		Tertius Chandler	Four thousand years of urban growth	p542