United States. Census Office. 6th Census, 1840, & United States. National Archives and Records Service. (1974). 1840 Census schedules of mines, agriculture, commerce, and manufacturing for Massachusetts. National Archives.
Chicago-viite (17. p.)United States. Census Office. 6th Census, 1840, ja United States. National Archives and Records Service. 1840 Census Schedules of Mines, Agriculture, Commerce, and Manufacturing for Massachusetts. Washington, D.C.: National Archives, 1974.
MLA-viite (8. p.)United States. Census Office. 6th Census, 1840, ja United States. National Archives and Records Service. 1840 Census Schedules of Mines, Agriculture, Commerce, and Manufacturing for Massachusetts. National Archives, 1974.
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