^Massachusetts Archives Vital Records, Birth of Harvey R Ball, 1921, vol.144, p.120
^"United States Census, 1930," database with images, FamilySearch(https://familysearch.org/ark:/61903/1:1:XQTF-P94 : accessed 10 May 2018), Ernest G Ball, Worcester, Worcester, Massachusetts, United States; citing enumeration district (ED) ED 109, sheet 20B, line 75, family 287, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 971; FHL microfilm 2,340,706. "نسخة مؤرشفة". مؤرشف من الأصل في 2021-11-14. اطلع عليه بتاريخ 2022-12-20.{{استشهاد ويب}}: صيانة الاستشهاد: BOT: original URL status unknown (link)
