Source of map: Southall, J.E. Wales – 1891 Census Map: Map of Wales showing Welsh language distribution according to census districts in five categories (from under 10% to over 80%). Cymraeg: Map o Gymru yn dangos dosbarthiad defnydd yr iaith Cymraeg yn ôl ardal mewn pum categori (o dan 10% i dros 80%). Data o’r Cyfrifiad 1891. Image held by the National Library of Wales / Llyfrgell Genedlaethol Cymru. Online at Wikimedia Commons (accessed 2nd Oct. 2023).
