The 'Cymraeg Clir' handbook by Cen Williams contains practical guidelines to help you write clear, understandable Welsh.

Cymraeg Clir, Canllawiau Iaith, Cen Williams, Gwasg Dwyfor 1999 (ISBN 1 898817 49 9)

To order a copy, please contact the main office at Canolfan Bedwyr or alternatively download a free copy.