- [S53] Register of Births, Marriages, and Deaths of Scotland, Church of Jesus Christ of Latter-day Saints, (Church of Jesus Christ of Latter-day Saints), index entry for Martha Dunlop Walker (Reliability: 1), 20 Aug 2015.
- [S15] 1870 United States Federal Census, (National Archives and Records Administration), M593., roll 0891. Union County, New Jersey. Plainfield township, p. 670-B (stamped), dwelling 875, family 965, Duncan Walker (Reliability: 3), 16 Aug 2011.
- [S52] Parish Registers for Greenock, 1698-1854, Church of Scotland. Parish Church of Greenock, (Genealogical Society of Utah), Film Number: 1041065; (Reliability: 3), 16 Aug 2011.