"United States Census, 1920," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MZQM-53G : accessed 20 Apr 2014), Walter Hoogstra in household of Tennis Niemeyer, Grand Rapids Ward 3, Kent, Michigan, United States; citing sheet 3A, family 48, NARA microfilm publication T625, FHL microfilm 1820779.