- [S82] Sheffield & District Family History Society, Sheffield Parish Baptisms, (FindMyPast.com), 4 May 2016, index entry for William Richard Parkin (1841).
- [S33] The National Archives of the UK, 1851 England Census, (Public Record Office), 22 Sep 2015, Ashton Under Lyne parish, Lancashire, England. p. 20, John Parkin household, citing PRO HO 107/2233.
- [S32] castlegarden.org, Castle Garden Immigration Records, 22 Aug 2010 (Reliability: 2).
- [S11] 1880 United States Federal Census, (National Archives and Records Administration), 22 Aug 2010, roll 0780. Essex County, New Jersey. East Orange township, ED 99, p. 520-B, dwelling 222, family 260, William R. Parkin household, T9. (Reliability: 3).
- [S17] New Jersey State Library, Records of Births, Marriages, and Deaths of New Jersey, 1848-1900, (The Genealogical Society of Utah: Salt Lake City, Utah; 1969), 22 Aug 2010, Film Number: 589831; Reference Number: Vol 10; (Reliability: 1).