Cyngor Sir Dyfed: Adran Priffyrdd a Thrafnidiaeth/Dyfed County Council: Highways and Transportation Department Ychwanegu i'r clipfwrdd P1/25 Ffeil 1978-1979 Rhan oPapurau Gwynfor Evans/Gwynfor Evans Papers, Dyfed (Wales). Highways and Transportation Dept.