See for example:
Number 8, Papers of Father Maurus O Faolain. Letters in English:
Numbers 83-84, Letters from Agnes J. MacHale, 34 Brewer Street, Golden Square, London West.

Number 83, asking permission on behalf of the secretary of the London Gaelic League, Mr [Fionan] Mac Coluim, to publish Fr Maurus's arrangement of 'Cillecash' as sung by Mr P. O'Shea and requesting other suitable airs, 20 July 1901.

Number 84, relating publication rights, 6 August 1901.

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Guide:
Padraig O Machain, 'Catalogue of Irish Manuscripts in Mount Melleray Abbey, Co. Waterford' (Dublin: Dublin Institute for Advanced Studies, 1991).

The library at Mount Melleray Abbey, Co. Waterford, houses a small collection of Irish 
manuscripts of the eighteenth and nineteenth centuries. This collection of manuscripts was 
chosen as a pilot undertaking of the Irish Script On Screen project (see link above).