Are you asking for modern day publications on Clontarf and Boru or original source material?

Much of the original source material would be found in the Inisfallen Annals and the Annals of Ulster. The Cogadh Gáedhel re Gallaibh is a slightly later text [early 12th century] but has its value.

I will recommend some modern day academic authors who have done research on Brian:

Seán Duffy has published Brian Boru and the Battle of Clontarf.

Darren McGettigan has published The Battle of Clontarf, Good Friday 1014.

One of the best sources is Donnchadh Ó Corráin's Ireland Before the Normans. This was first published in the early 1970s but Ó Corráin was the first academic to point out the complexities of the relationship that the Vikings had with the Irish kings.

I'm afraid I don't know of any fiction that would accurately depict the period. As you likely know there has been a lot of talk about fictional films on the subject but none have come to light that I know of.

There was a documentary RTÉ and PBS did about 10 years ago that did a segment on Brian Boru and his life. Donnchadh Ó Corráin, Seán Duffy and Charlie Doherty were interviewed. They visited the site of the Clontarf battle and the site of Brian's home at Kincora. It's called In Search of Ancient Ireland. It may be available somewhere on DVD.