Easy ones first
United States Census, 1930," database with images, FamilySearch(https://familysearch.org/ark:/61903/1:1:XH82-WN7 : accessed 9 July 2018), Stephen J Ditko in household of Stephen Ditko, Johnstown, Cambria, Pennsylvania, United States; citing enumeration district (ED) ED 70, sheet 7A, line 42, family 116, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 2012; FHL microfilm 2,341,746.
United States Census, 1940," database with images, FamilySearch(https://familysearch.org/ark:/61903/1:1:KQXB-KY7 : accessed 9 July 2018), Steven Ditko in household of Steven Ditko, Ward 18, Johnstown, Johnstown City, Cambria, Pennsylvania, United States; citing enumeration district (ED) 11-106, sheet 12B, line 59, family 205, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 3455.
United States Social Security Death Index," database, FamilySearch(https://familysearch.org/ark:/61903/1:1:J27H-D27 : 20 May 2014), Stephen Ditko, May 1966; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).