Cyfres Celc Cymru: Maes y Magnelau - Hanes Gwersyll Milwrol Trawsfynydd Hanes Gwersyll Milwrol Trawsfynydd O'Brien Keith Heftet / 2018 / Walisisk
Danger Farm, A History of Trawsfynydd Artillery Camp A History of Trawsfynydd Artillery Camp O'Brien Keith Heftet / 2021 / Engelsk
Charlie Hustle The Rise and Fall of Pete Rose, and the Last Glory Days of Baseball O'Brien Keith Heftet / 2025 / Engelsk
Paradise Falls A Deadly Secret, a Cover-Up, and the Women Who Forged the Modern Environmental Movement O'Brien Keith Heftet / 2023 / Engelsk
Applications of Computer Modeling for Extrusion and Other Continuous Polymer Processes O'Brien Keith Innbundet / 1992 / Engelsk
Charlie Hustle The Rise and Fall of Pete Rose, and the Last Glory Days of Baseball O'Brien Keith Innbundet / 2024 / Engelsk
Traws-Olwg - Trawsfynydd a'r Ardal Fel y Bu Trawsfynydd a'r Ardal Fel y Bu Lolfa, Y Heftet / 2017 / Engelsk
