Edwards, N. John Frost and the Chartist movement in Wales. Western Valleys Labour Classes.
Lua i Stíl Chicago (17ú heag.)Edwards, Ness. John Frost and the Chartist Movement in Wales. Abertillery: Western Valleys Labour Classes.
Lua MLA (8ú heag.)Edwards, Ness. John Frost and the Chartist Movement in Wales. Western Valleys Labour Classes.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.