"Montana, County Marriages, 1865-1950," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/F37C-92W : accessed 08 Sep 2014), Francher A. Gregory and Lillian R. Strong, 15 Oct 1925; citing Bk9 pg860, Livingston, Park, Montana; FHL microfilm 1940412.
"United States Census, 1930", database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XCMT-BJC : 8 December 2015), Frank A Gregory, 1930. District ED 51 Sheet Number and Letter 1A Household ID 1 Line Number 1 Affiliate Name The U.S. National Archives and Records Administration (NARA) Affiliate Publication Number T626 Affiliate Film Number 1259 GS Film Number 2340994 Digital Folder Number 004951847 Image Number 00828.
"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:VBQ4-HWN : accessed 21 August 2018), Frank Gregory, Ward 1, Livingston, School District 4 Livingston, Park, Montana, United States; citing enumeration district (ED) 34-3, sheet 6B, line 70, family 130, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 2226.