Hochfelder. The Telegraph in America, 1832â€"1920. Johns Hopkins University Press.
Cita Chicago (17th ed.)Hochfelder. The Telegraph in America, 1832â€"1920. Johns Hopkins University Press.
Cita MLA (8th ed.)Hochfelder. The Telegraph in America, 1832â€"1920. Johns Hopkins University Press.
Atenció: Aquestes cites poden no estar 100% correctes.