Gruber Family Papers, Collection ID-0367, Box: Gro - Gu, Folder: Gruber. Concordia Historical Institute.
Gruber Family Papers, Collection ID-0367, Box: Gro - Gu, Folder: Gruber. Concordia Historical Institute. https://concordiahistoricalinstitute.libraryhost.com/repositories/2/resources/1162 Accessed January 10, 2025.
