Não informado. (1941). Bell Telephone Magazine. American Telephone and Telegraph Company.
Chicago (17e ed.) BronvermeldingNão informado. Bell Telephone Magazine. New York: American Telephone and Telegraph Company, 1941.
MLA (8e ed.) BronvermeldingNão informado. Bell Telephone Magazine. American Telephone and Telegraph Company, 1941.
Let op: Deze citaties zijn niet altijd 100% accuraat.