Griffiths, Bruce, Glyn Jones, Dafydd (1995) Geiriadur yr Academi: The Welsh Academy English–Welsh Dictionary[1], Cardiff: University of Wales Press, →ISBN
Delyth Prys, J.P.M. Jones, Owain Davies, Gruffudd Prys (2006) Y Termiadur: termau wedi'u safoni; standardised terminology[2] (in Welsh), Cardiff: Awdurdod cymwysterau, cwricwlwm ac asesu Cymru (Qualifications curriculum & assessment authority for Wales), →ISBN
