Columbia subject headings:
Electrical engineering--Periodicals.
Industrial management--Periodicals.
Telegraph--Periodicals.
Telephone--Periodicals.
Harvard subject headings:
Electrical engineering--Periodicals
Industrial management--Periodicals
Telegraph--Periodicals.
Telephone--Periodicals
Princeton subject headings:
Electrical engineering--Periodicals.
Industrial management--Periodicals.
Periodicals.
Telegraph--Periodicals.
Telephone--Periodicals.