1912
1914

1913

Ericsson 50-line switchboard
1913: Ericsson 50-line switchboard
1913: AT&T Annual Report, 1913
1913: U.S. drops antitrust suit against AT&T, essentially cementing its quasi-monopoly
1913: Ericsson 1913 switchboards and accessories catalog (abridged)
1913: Ericsson 1913 switchboards catalog (with great illustrations at end)