Tolong jelaskan mengenai Bacaan lanjut dari Llywelyn ap Gruffudd

Gwynfor Evans (2001) Cymru O Hud Abergwyngregyn

Gwynfor Evans (2002) Eternal Wales Abergwyngregyn

John Edward Lloyd (1911) A history of Wales from the earliest times to the Edwardian conquest (Longmans, Green & Co.)

Kari Maund (2006) The Welsh kings: warriors, warlords and princes (Tempus)

T. Jones Pierce Cymdeithas Hanes Sir Caernarfon- Trafodion (1962) Aber Gwyn Gregin

J. Beverley Smith (2001) Llywelyn ap Gruffudd: Prince of Wales (University of Wales Press)

David Stephenson (1984) The governance of Gwynedd (University of Wales Press)

Y Traethodydd (Gorffennaf 1998) Tystiolaeth Garth Celyn