Mae'r grŵp hwn yn cynnwys llawysgrifau, teipysgrifau a phroflenni rhai o gyhoeddiadau Ambrose Bebb, a chopi llawysgrif o un gwaith anghyhoeddedig, 1934-1955.

Papurau Pennar Davies, 1913-1999, yn cynnwys copïau teipysgrif o'i weithiau llenyddol, ynghyd â phapurau academaidd a phapurau llenyddol.

Papurau llenyddol Amanwy, yn cynnwys cerddi, caneuon a gweithiau mewn amryw ffurf, 1909-1953, yn enwedig pryddestau, 1909-1953, telynegion, 1910-1946, a sonedau, 1929-[1953]; rhyddiaith, 1924-1949, sy'n cynnwys darlithoedd, anerchiadau, storiâu byrion a nodiadau; sgriptiau radio,1942-1953; deunydd printiedig yn cynnwys emynau gan Amanwy a gweithiau ganddo ef ac eraill, 1919-1953; torion o'r wasg,1919-1945; a llythyrau,1950-1975. Gweler hefyd Trefniant = Literary papers of Amanwy, comprising poems, songs and other works of various forms, 1909-1953, notably pryddestau, 1909-1953, lyrics, 1910-1946, and sonnets, 1929-[1953]; prose works, 1924-1949, which include lectures, addresses, short stories and notes; radio scripts, 1942-1953; printed materials including hymns by Amanwy and works by him and others, 1919-1953; newspaper cuttings, 1919-1954; and letters, 1950-1975. See also Arrangement.

Papers of Harri Webb, [c. 1919]-1995, including poetry, 1942-1989; reviews and reader's reports, 1974-1986; correspondence with publishers, broadcasters and editors relating to Webb's work, 1949-1995; correspondence from literary and artistic figures, [1940s]-1983; political correspondence, 1964-1974; political press cuttings, 1952-1981; papers relating to Plaid Cymru, 1961-1978, and Scottish politics, 1967-1969; and personal papers, [c. 1919]-1984.

A collection of Harri Webb's diaries. This group remains uncatalogued.

Papers relating to the life and career of Edward Morgan Humphreys, including letters to E. Morgan Humphreys, from several prominent Welsh figures, 1900x1955, relating to professional matters, such as his articles and contributions to newspapers, requests for articles, radio talks, addresses, literary works, public appointments, his involvement with the eisteddfod and various committees; together with some letters relating to personal affairs, politics and literary matters and letters written to him in his role as an editor; miscellaneous and family ('Dyffryn') correspondence, which are mostly letters of the families of E. Morgan Humphreys' great-grandfather, the Rev Richard Humphreys, and of his grandfather, the Rev Edward Morgan, [1800]x1953; articles, radio scripts and addresses by E. Morgan Humphreys, 1902x1955; together with some personal and family papers, 1841x1955; articles, poetry, adjudications and letters to the editor of Y Genedl etc., by T. Gwynn Jones, 1890x1949; and other miscellaneous papers accumulated by E. Morgan Humphreys, [1762]x1955. Some of the family correspondence was published in 'Some Nineteenth Century Letters', in The Transactions of the Honourable Society of Cymmrodorion, 1925-1926.