The Bodyguard series (in reading order)
HOSTAGE
RANSOM
AMBUSH
TARGET
ASSASSIN
FUGITIVE
The Young Samurai series (in reading order)
THE WAY OF THE WARRIOR
THE WAY OF THE SWORD
THE WAY OF THE DRAGON
THE RING OF EARTH
THE RING OF WATER
THE RING OF FIRE
THE RING OF WIND
THE RING OF SKY
Available as ebook
THE WAY OF FIRE