* The Complete Tolkien Companion (2006)
* Tolkien:A Biography (2013)
* The World of Tolkiens The Lord of the Rings (2014)
* The Fellowship of the Ring:A Reader's Companion (2016)
* The Two Towers:A Reader's Companion (2017)
* The Return of the King:A Reader's Companion (2018)
Artikler
* "Tolkiens mytologi" (2007)
* "Ringenes Herre:A Cultural History" (2008)
* "Tolkien og den store krigen" (2014)
* "The Inklings:A Literary Fellowship" (2015)
* "Ringenes Herre:En guide for de forvirrede" (2016)
Annet
* Redaktør, J.R.R. Tolkien Encyclopedia:Scholarship and Critical Assessment (2006)
* Produsent, The Lord of the Rings:The Return of the King Extended Edition DVD (2004)
* Forteller, Hobbiten lydbok (2004)
* Gjesteforeleser, University of Oxford (2007-2018)
* Gjesteforsker, University of Leeds (2019-i dag)