Greyland: D.U.M.B.s (Deep Underground Military Bases) - Book 1
2014
Rescueplan: D.U.M.B.s (Deep Underground Military Bases) - Book 3
2014
Oceandeep: D.U.M.B.s (Deep Underground Military Bases) - Book 2
2014
Purifier: D.U.M.B.s (Deep Underground Military Bases) - Book 7
2020
Moonbase: D.U.M.B.s (Deep Underground Military Bases) – Book 4
2014
Wormwood: D.U.M.B.s (Deep Underground Military Bases) - Book 5
2016