Columbia subject headings:
Electrical engineering--Bibliography.
Electricity--Bibliography.
Magnetism--Bibliography.
Rare books.
Sympathetic telegraph.
Telegraph--Bibliography.
Harvard subject headings:
Electrical engineering--Bibliography--Catalogs.
Electrical engineering--Bibliography.
Electricity--Bibliography
Electricity--Bibliography--Catalogs
Magnetism--Bibliography.
Rare books
Sympathetic telegraph.
Telegraph--Bibliography.
Princeton subject headings:
Electrical engineering--Bibliography.
Electricity--Bibliography.
Magnetism--Bibliography.
Rare books.
Sympathetic telegraph.
Telegraph--Bibliography.