Torrieri, Nancy; Davis, James (November 1994). "4: States, Counties and Statistically Equivalent Entities". Geographic Areas Reference Manual(PDF). United States Department of Commerce, Economics and Statistics Administration, Bureau of the Census.
"County Government". Massachusetts Official Commonwealth Website (Office of Secretary of Commonwealth). Archived from the original on 2022-02-06. Retrieved 2018-12-02.
"County Government". Massachusetts Official Commonwealth Website (Office of Secretary of Commonwealth). Archived from the original on 2022-02-06. Retrieved 2018-12-02.