Nihon Denshin Denwa Kabushiki Kaisha

• '88 NTT, sono hito to soshiki
• Denki Tsūshin Shingikai, NTT no arikata ni tsuite no Tokubetsu Bukai goshitsumon e no kaitō
• Kagōbutsu jōhō tō no riyō kōdoka no tame no kyōyō nettowāku kōsei hōshiki kenkyū hōkokusho