Columbia subject headings:
Harvard subject headings:
Electric industries--Japan--History.
Nihon Denki Kabushiki Kaisha--History.
Telecommunication systems--Japan--History.
Telephone--Japan--History.
Princeton subject headings:
Electric industries--Japan--History.
Nihon Denki Kabushiki Kaisha--History.
Telecommunication systems--Japan--History.
Telephone--Japan--History.