Não informado. (1918). National Bureau of Standards Handbook. Government Printing Office.
Chicago-referens (17:e uppl.)Não informado. National Bureau of Standards Handbook. Washington: Government Printing Office, 1918.
MLA-referens (8:e uppl.)Não informado. National Bureau of Standards Handbook. Government Printing Office, 1918.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.