Columbia subject headings:
International telegraph convention, 1865--Revisions (1875 Regulations) 1925.
Telegraph (International law)--Congresses.
Telegraph and telephone--Law and legislation.
Harvard subject headings:
International telegraph convention,--Revisions (1875 Regulations) 1925.
Telegraph (International law)--Congresses.
Telegraph--Law and legislation
Telephone--Law and legislation
Princeton subject headings: