The ISBN of The Time Machine is 0-89375-345-9.
The ISBN of Machine of Death is 9780982167120.
The ISBN of The Republican Noise Machine is 1400048753.
The ISBN of The Winter of Frankie Machine is 1400044987.
The ISBN of The Omen Machine is 0-7653-2772-4.
The ISBN of The Soul of a New Machine is 978-0316491709.
The ISBN of Idiots in the Machine is 0-9706730-0-0.
The ISBN of Lord Kelvin's Machine is 0-87054-163-3.
The ISBN of Souls in the Great Machine is 0-7653-4457-2.
The ISBN of A Thief of Time is 9780061000041.
The ISBN of The Masks of Time is 0345234464.
The ISBN of Angel Time is 9781400043538.
The ISBN of Time Benders is 0440412145.