United States. Census Office. 6th Census, 1840, & United States. National Archives and Records Service. (1973). Schedule of mines, agriculture, commerce, manufactures, etc. of 1840 census for Illinois. National Archives.
Dyfyniad Arddull ChicagoUnited States. Census Office. 6th Census, 1840, and United States. National Archives and Records Service. Schedule of Mines, Agriculture, Commerce, Manufactures, Etc. of 1840 Census for Illinois. Washington, D.C.: National Archives, 1973.
Dyfyniad MLAUnited States. Census Office. 6th Census, 1840, and United States. National Archives and Records Service. Schedule of Mines, Agriculture, Commerce, Manufactures, Etc. of 1840 Census for Illinois. National Archives, 1973.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.