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.
Lua i Stíl Chicago (17ú heag.)United States. Census Office. 6th Census, 1840, agus United States. National Archives and Records Service. 1840 Census Schedules of Mines, Agriculture, Commerce, and Manufacturing for Massachusetts. Washington, D.C.: National Archives, 1974.
Lua MLA (8ú heag.)United States. Census Office. 6th Census, 1840, agus 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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