Barons, Baronies and Bishops' Regalia

Extract from

Sir Thomas Edlyne Tomlins (1811). The law-dictionary: explaining the rise, progress, and present state, of the English law: defining and interpreting the terms or words of art; and comprising copious information on the subjects of law, trade, and government. I. Riley. pp. 265–5.

See also

David Knowles (2 January 1951). The Episcopal Colleagues of Archbishop Thomas Becket: Being the Ford Lectures Delivered in the University of Oxford in Hilary Term, 1949. Cambridge University Press. pp. 150–. ISBN 978-0-521-05493-5. 

William Mudford (1834). "By What Rights Do Bishops Sit In Parliament". The Canterbury Magazine. Office of the Kentish Observer. pp. 64–.

Sir Robert Warrand Carlyle; Alexander James Carlyle (1903)

A history of mediæval political theory, Volume 4, p.342-83 

Postan, M. M., and John Hatcher. “Population and Class Relations in Feudal Society.” Past & Present, no. 78, 1978, pp. 24–37. JSTOR, www.jstor.org/stable/650370

Gerhoh of Reichersberg