Source Data Reference for:

City = Alkmaar
Time = 1850

City	Year	Size	Size Comment	Year Comment	Author	Title	Location
Alkmaar	1840	9,500			Jan Lahmeyer	http://www.populstat.info/	n/a
Alkmaar	1850	10,000			Paul Bairoch	La population des villes europeennes de 800 a 1850