"England and Wales Census, 1841," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MQJD-NRV : 12 December 2017), Maria Clark in household of Wm Clark, St Marylebone, Middlesex, England; from "1841 England, Scotland and Wales census," database and images, findmypast (http://www.findmypast.com : n.d.); citing PRO HO 107, The National Archives, Kew, Surrey.
"England and Wales Census, 1851," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:SGF5-TF1 : 1 November 2017), Maria Clark, Marylebone, Middlesex, England; citing Marylebone, Middlesex, England, p. 56, from "1851 England, Scotland and Wales census," database and images, findmypast (http://www.findmypast.com : n.d.); citing PRO HO 107, The National Archives of the UK, Kew, Surrey.
"England and Wales Census, 1861," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M7GH-TNR : 10 December 2017), Maria Clark, Marylebone, London, Middlesex, England; from "1861 England, Scotland and Wales census," database and images, findmypast (http://www.findmypast.com : n.d.); citing PRO RG 9, The National Archives, Kew, Surrey.
"England and Wales Census, 1871", database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:VRJM-338 : 9 December 2017), Maria Clark, 1871.
"England and Wales Census, 1881," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:Q273-FSBP : 10 December 2017), Judith Clark in household of Maria C Andrews, St James Westminster, London,Middlesex, England; from "1881 England, Scotland and Wales Census," database and images, findmypast (http://www.findmypast.com : n.d.); citing p. 22, Piece/Folio 127/28, The National Archives, Kew, Surrey; FHL microfilm 101,774,341.