Guide to Manuscripts in the Bentley Historical Library by Thomas E. Powers and William H. McNitt (Ann Arbor, 1976), no. 33; Guide to Manuscripts in the Michigan Historical Collections of the University of Michigan by Robert M. Warner and Ida C. Brown (Ann Arbor, 1963); and Guide to Manuscript Collections in Michigan, prepared by the Michigan Historical Records survey project for the Works Projects Administration (Detroit, 1941–42), 2 vols. For the North Russian AEF expedition collections, there is a "Bibliographic Note" in Richard M. Doolen's Michigan's Polar Bears (Ann Arbor, 1965), which is Bulletin no. 14 of the Michigan Historical Collections.
Note: The James B. Angell papers in the Bentley Library include letters from White which may be relevant.