"United States World War II Draft Registration Cards, 1942", index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/V12D-CGD : accessed 03 Oct 2014), Sidney Zuidema, 1942.
"United States Census, 1930," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/XQRT-GNY : accessed 03 Oct 2014), David Zuidema in household of Sydney A Zuidema, Athol, Worcester, Massachusetts, United States; citing enumeration district (ED) 0126, sheet 32A, family 911, NARA microfilm publication T626, roll 961.