↑ Fryde, E. B.; Greenway, D. E.; Porter, S.; Roy, I. (1986). Handbook of British Chronology (Thirded.). Cambridge: Cambridge University Press. p.345. ISBN0-521-56350-X.
↑ 'Raphoe and Derry in the 12th and 13th Centuries' Gwynn, A pp84-100: 'Donegal Annual' IV no.2 (1959)
