Não informado. (1989). NTT Review. Nippon Telegraph and Telephone Corporation.
Chicago (17e ed.) BronvermeldingNão informado. NTT Review. Tokyo: Nippon Telegraph and Telephone Corporation, 1989.
MLA (8e ed.) BronvermeldingNão informado. NTT Review. Nippon Telegraph and Telephone Corporation, 1989.
Let op: Deze citaties zijn niet altijd 100% accuraat.