Papurau yn ymwneud ag amrywiaeth eang o weithgareddau Brinli yn cynnwys llyfrau ysgol a defnyddiau addysgiadol eraill, 1915-1977; papurau cyfreithiol, yn bennaf gohebiaeth a nodiadau, 1918-1980; cofnodion Cyngor Dosbarth Trefol Maesteg, 1927-1976; papurau Undeb Annibynwyr Cymru, 1931-1976; hanes lleol, 1927-1971; Amgueddfa Genedlaethol Cymru, 1976-1981; deunydd yn ymwneud â'i gyfrolau ar Iolo Morganwg, [1974]-[1979]; Yr Eisteddfod Genedlaethol, 1926-1981, a beirniadaethau eisteddfodol, 1943-1981; torion papur newydd, 1920-1980; rhyddiaith Brinli, 1919-1978, a barddoniaeth, 1932-1981; gweithiau llenyddol eraill ganddo ef ac eraill, 1913-1978; gohebiaeth bersonol, 1909-1981; papurau eraill personol a theuluol, 1887-1981; ei ddyddiaduron, 1922-1981, a rhai ei dad, Joshua, 1893-1944; cofnodion Cylchdaith Annibynnwyr De Morgannwg, 1841-1978, Capel Siloh, 1850-1977, Eisteddfod Genedlaethol 1932 a 1948 ac eraill, 1932-1981; papurau Lewis Davies, Y Cymer (1863-1951), awdur nofelau i blant, [1849?]-1946, yn cynnwys sawl llyfr rent o Benderyn; papurau, 1883-1925, Rhys Dafydd Morgan (1851-1934), cyfieithydd o Gymro a fferyllydd ym Maesteg; papurau, 1882-1968, 'Wil Ifan' William Evans (1882-1968), archdderwydd, gweinidog yr Annibynwyr ac awdur; a phapurau, 1929-1979, 'Trefin, Edgar Phillips (1889-1962), bardd ac archdderwydd. = Papers concerning a wide variety of Brinli's activities including school books and other educational material, 1915-1977; legal papers, mainly correspondence and notes, 1918-1980; Maesteg Urban District Council records, 1927-1976; the Welsh Congregational Union papers, 1931-1976; local history, 1927-1971; the National Museum of Wales, 1976-1981; material relating to his books on Iolo Morganwg, [1974]-[1979]; the National Eisteddfod, 1926-1981, and eisteddfod adjudications, 1943-1981; newspaper cuttings, 1920-1980; Brinli's prose, 1919-1978, and poetry, 1932-1981; other literary works by him and others, 1913-1978; personal correspondence, 1909-1981; other personal and family papers, 1887-1981; his diaries, 1922-1981, and those of his father, Joshua, 1893-1944; records of the South Glamorgan Congregational Circuit, 1841-1978, Siloh Chapel, 1850-1977, and of the National Eisteddfodau of 1932 and 1948 and others, 1932-1981; papers of Lewis Davies, Y Cymer (1863-1951), author of children's novels, 1849-1946, including several rate books for Penderyn; papers, 1883-1925, of Rhys Dafydd Morgan (1851-1934), Welsh translator and Maesteg pharmacist; papers, 1882-1968, of 'Wil Ifan', William Evans (1882-1968), archdruid, congregational minister and author; and papers, 1929-1975, of 'Trefin', Edgar Phillips (1889-1962), poet and archdruid.

Papurau Dyddgu Owen, 1934-1991, yn cynnwys drafftiau teipysgrif a llawysgrif o'i nofelau a gweithiau llenyddol eraill,1953-1986; amrywiol darlithoedd ac anerchiadau, 1950au-1980au; sgriptiau ar gyfer radio a theledu, 1957-1976; dyddiaduron, 1978-1989; llyfrau nodiadau, 1957-1970; gohebiaeth, 1946-1991; dyddiaduron, 1978-1989; llyfrau lloffion o dorion o'r wasg, 1957-1970; papurau amrywiol yn ymwneud â'i diddordebau, 1969-1977; a phapurau Sarah Ceridwen (Ceri) Davies,1944-1991, yn cynnwys cofnodion gweinyddol cymdeithas 'Cyfeillion Ellis Wynne' [Lasynys] = Papers of Dyddgu Owen, 1934-1991, including typed and manuscripts drafts of her novels and other literary works, 1953-1986; various lectures and addresses, 1950s-1980s; radio and television scripts, 1957-1976; diaries, 1978-1989; notebooks, 1957-1970; correspondence, 1946-1991; diaries, 1978-1989; scrap books of press cuttings, 1957-1970; miscellaneous papers relating to her interests, 1969-1977; and papers of Sarah Ceridwen (Ceri) Davies, 1944-1991, which include administrative records of the society 'Cyfeillion Ellis Wynne' [Lasynys].

Casgliad o lythyrau a chyfansoddiadau a anfonwyd at W. J. Gruffydd a T. J. Morgan ar gyfer eu cynnwys yn Y Llenor, 1891-1988. Ceir hefyd bapurau a gasglwyd gan T. J. Morgan, sef papurau Llewellyn Llewellyn (Llywelyn Ddu o Lan Tawe), Abertawe, [c. 1880]-[c. 1924]; papurau'r Parch Ben Davies, Panteg, 1862-1964; ychydig o bapurau R. G. Berry a phapurau T. J. Morgan ar R. G. Berry, 1885-1962; a thair cyfrol o dorion papur newydd, 1850-1950.

Ninety-four letters, 1919-1984, in Welsh and English, to Saunders Lewis from various correspondents, together with a few draft letters from Saunders Lewis and four letters to Margaret Lewis, written during her husband's imprisonment in 1937. Subjects discussed include Welsh nationalism, the award of DLitt honoris causa to Saunders Lewis, the Welsh Burial Grounds issue, 1928, and literary topics; enclosures include a copy of a draft constitution and articles of agreement, 1934, relating to self-government for Wales (ff. 161-95). Among the main correspondents are Edward Glyn Jones (13) 1919-28, Robert Williams Parry (14) 1927-44, John Arthur Price (5) 1928, E. Prosser Rhys (3) 1927-9, D. J. Williams, Fishguard (7) 1948-67, and Griffith John Williams (3) 1935-56.

Papurau Harri Gwynn, 1924-1997, yn cynnwys gohebiaeth gynnar rhyngddo a'i wraig Eirwen Gwynn; llythyrau oddi wrth lenorion; cerddi Harri Gwynn gan gynnwys cyfieithiadau i'r Saesneg a Sbaeneg o'i bryddest 'Y Creadur' a chyfieithiadau o ganeuon; sgriptiau radio; personalia; papurau'n ymwneud â'r Mudiad Gwerin; ynghyd â llythyrau a chardiau cydymdeimlad a anfonwyd i'w deulu; a theyrngedau iddo. = Papers of Harri Gwynn, 1924-1997, comprising early correspondence between him and his wife; letters from literary figures; poems by Harri Gwynn including English and Spanish translations of his poem in free metre (pryddest) 'Y Creadur' ('The Creature') and translations of his songs; radio scripts; personalia; papers relating to the movement Gwerin (Folk); together with letters and sympathy cards sent to his family; and tributes to him.

Papurau personol, proffesiynol a llenyddol J. Gwyn Griffiths, 1926-2001, gan gynnwys llythyrau oddi wrth gyfeillion, ysgolheigion a llenorion. Ceir papurau'n ymwneud â'i ddiddordeb mewn gwleidyddiaeth ac fel adolygydd llyfrau, ynghyd â rhai o bapurau ei wraig Kate Bosse-Griffiths a'i frawd D. R. Griffith.

Papurau Carneddog a rhai a gasglwyd ganddo, 1743-1947, yn cynnwys rhyddiaith a barddoniaeth ganddo ef ac eraill ar gyfer eu cyhoeddi, yn cynnwys colofn 'Manion o'r Mynydd'; torion papur newydd o'i waith ef ac eraill; gwaith gan awduron adnabyddus a gasglodd, yn eu mysg cerddi David W. Morris ('Dewi Glan Dulas', 1853-95) a dyfyniadau cywyddwyr; ei nodiadau bywgraffiadol ar awduron; papurau personol a theuluol, yn cynnwys llythyrau a anfonwyd ganddo o Iwerddon, pan oedd yn gwella o salwch yn 1899; swm sylweddol o ddeunydd yn ymwneud â hanes Beddgelert a phlwyfi cyfagos, yn cynnwys llyfrau lloffion gyda nodiadau llawn, copi llawysgrif o hanes Beddgelert a nifer o deuluoedd lleol, a llyfr rent Carneddi, 1743-1832; a nifer fawr o lythyrau at Garneddog, llawer ohonynt yn ymwneud â'i golofn yn yr Herald, a hefyd yn cynnwys llythyrau gan awduron Cymreig a llythyrau o UDA ac Awstralia. = Papers, 1743-1947, of and collected by Carneddog, comprising prose and poetry by him and others towards publications including the 'Manion o'r Mynydd' column; newspaper cuttings of his own work and that of others; works by well-known authors collected by him, including poems of David W. Morris ('Dewi Glan Dulas', 1853-95) and quotations from the cywyddwyr; biographical notes by him on authors; personal and family papers, including letters sent by him from Ireland, where he was recuperating from illness in 1899; a considerable amount of material relating to the history of Beddgelert and neighbouring parishes, including fully annotated scrapbooks, a manuscript history of Beddgelert and of several local families, and a rent book from Carneddi, 1743-1832; and a large number of letters to Carneddog, many of them relating to his column in the Herald, and also including letters of Welsh authors and letters from the USA and Australia.