^Lewis Morris Hallowell Death Certificate. Died January 14, 1909. Massachusetts Vital Records, 1840–1911. New England Historic Genealogical Society, Boston, Massachusetts.
^Harriet Hallowell - October 15, 1917. Passport Applications, January 2, 1906–March 31, 1925. NARA Microfilm Publication M1490, 2740 rolls. General Records of the Department of State, Record Group 59. National Archives, Washington, D.C.
