- [S336] Madaline SIefke, "Re: Estills and Siefkes," e-mail message from e-mail address (Ithaca, New York) to Alton Donnell, 16 July 2025. Hereinafter cited as "Re: Estills and Siefkes."
- [S340] Thompson D. Donnell, online https://www.familysearch.org/en/tree/person/details/…. Hereinafter cited as Thompson D. Donnell.
- [S341] Andrew Jackson Donnell, online https://www.familysearch.org/en/tree/person/details/…. Hereinafter cited as Andrew Jackson Donnell.
- [S342] Henry Thomas Donnell, online https://www.familysearch.org/en/tree/person/details/…. Hereinafter cited as HTD.
- [S343] Mark Twain Donnell, online https://www.familysearch.org/en/tree/person/details/…. Hereinafter cited as Mark Twain Donnell.
- [S355] Eric Tamayo, online https://www.facebook.com/eric.tamayo.165. Hereinafter cited as Eric Tamayo.
- [S366] "Books: The Hermit of Lambertville", Time Magazine (2 September 1957). Hereinafter cited as "The Hermit of Lambertville."
- [S382] Fitch, Brooklyn Eagle, Brooklyn, New York, 30 July 1941, p. 9. Hereinafter cited as Brooklyn Eagle.
- [S383] Ancestry.com, online www.ancestry.com, Jaimie Rice (Utah).