Burke 1866, p. 361. Burke, Sir Bernard (1866). A genealogical history of the dormant, abeyant, forfeited, and extinct peerages of the British empire. Harrison. p. 361.
Beatson 1806, p. 26. Beatson, Robert (1806). A political index to the histories of Great Britain & Ireland, or, a complete register of the hereditary honours, public offices, and persons in office: from the earliest periods to the present time. Vol. 3 (3 ed.). Longman, Hurst, Rees, and Orme. p. 26 (footnote).
