"United States Census, 1930", database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:X4CC-4H2 : accessed 21 February 2016), Ferdinand H Dickman in entry for William Dickman, Jackson, Putnam, Ohio, United States,1930.
"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:KWLC-8QM : accessed 21 February 2016), H Ferdinand Dickman in household of William Dickman, Jackson Township, Putnam, Ohio, United States; citing enumeration district (ED) 69-4, sheet 5B, family 87, NARA digital publication T627 (Washington, D.C.: National Archives and Records Administration, 2012), roll 3133.
"United States Social Security Death Index," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:V9QS-GZ4 : 9 January 2021), Ferdinand H Dickman, 18 May 1992; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).
Find A Grave: Memorial #218001701 for Ferdinand Henry Dickman in Chapel Gardens Cemetery, Elwell, Gratiot County, Michigan, USA.