Peterson, Peter, 1887 - 1960. Letters, 1918 - 1919. SMHC Collection 0138, Southern Minnesota Historical Center, Memorial Library, Minnesota State University, Mankato.
Peterson, Peter, 1887 - 1960. Letters, 1918 - 1919. SMHC Collection 0138, Southern Minnesota Historical Center, Memorial Library, Minnesota State University, Mankato. https://archivesspace.lib.mnsu.edu/public/repositories/4/resources/630 Accessed December 23, 2024.