Carlyle, Thomas. "Chapter V. The Fourth Estate". The French Revolution. 1. Diarsipkan dari versi asli tanggal 22 January 2000. Diakses tanggal 12 November 2009.
Macknight, Thomas (1858). "For the Liberty of the Press". History of the life and times of Edmund Burke. 1. London: Chapman and Hall. hlm. 462. OCLC3565018.
Hazlitt, William (1835). Character of W. Cobbett M. P. Finsbury, London: J Watson. hlm. 3. OCLC4451746. He is too much for any single newspaper antagonist...He is a kind of fourth estate in the politics of the country.
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Carlyle, Thomas. "Chapter V. The Fourth Estate". The French Revolution. 1. Diarsipkan dari versi asli tanggal 22 January 2000. Diakses tanggal 12 November 2009.