Just for clarity, are you more interested in the 1920s or the 1960s to 1990s? They are quite different periods and organisations.

The best one volume work is probably Richard English, *Armed Struggle: the history of the IRA * (2006) which covers 1916 to 2002 so I would start there.

For the Northern Ireland troubles

Peter Taylor, Provos is a book and TV series which contains some good interviews James Bowyer Bell, The Secret Army still holds up well enough Two books by journalists, Tim Pat Coogan, The IRA is quite sympathetic to republicanism though he is not pro violence while Ed Moloney, A Secret History of the IRA is more critical of the leadership. Both are well connected journalists but this means their sources are often not identified.

I quite like M.L.R. Smith (1995). Fighting for Ireland: The Military Strategy of the Irish Republican Movement.

For the 1920s IRA

*The Atlas of the Irish Revolution * is a collection of entries by pretty much every major historian of the period and covers a range of aspects of the IRA

The RTÉ documentary *The Irish Revolution * is good There are quite a few general texts on the revolution. Marie Coleman, The Irish Revolution 1913-23 is a good introduction (disclaimer, I’m married to her) Diarmaid Ferriter, A nation not a Rabble, The Irish Revolution 1913-23 is also fine.

The IRA's successive incarnations date back to the Irish Volunteers of 1913 and draw on earlier Republican traditions including the 19th-century Fenian movement, but if your interest is in the "Troubles" of 1968-98: there's a very good 7-part 2019 BBC series on the period titled The Troubles: a secret history including testimony from all sides of the conflict, if you can get your hands on it.

(Your English is fine, by the way, no need to apologise.)