2 published works would be useful for some of the collections described above: Peter O. Hiebert's Feeding the Hungry (1929) concerns American Mennonite Relief work in Russia in 1921–23; and Exiled by the Czar: Cornelius Jansen and the Great Mennonite Migration, 1874 by G. E. Reimer and G. R. Gaeddert (1956). In addition, there is an unpublished guide for each of these collections.
In addition to the preceding collections, there are many others which contain letters written from Russia to relatives in the U.S. after the migration of 1874, and correspondence from relatives dated in the 1930s.