U.S. Bureau of the Census. (1921). Census of manufacturers: 1921. Govt. Print. Off.
Lua i Stíl Chicago (17ú heag.)U.S. Bureau of the Census. Census of Manufacturers: 1921. Washington: Govt. Print. Off, 1921.
Lua MLA (9ú heag.)U.S. Bureau of the Census. Census of Manufacturers: 1921. Govt. Print. Off, 1921.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.