Original: ISBN 1-930051-22-0 Peter Singer, Ethics into Action: Henry Spira and the Animal Rights Movement (Lanham, MD: Bowman & Littlefield, 1998).
Simplified: ISBN 0-02-916195-9 Peter Singer, Ethics into Action: Henry Spira and the Animal Rights Movement (Lanham, MD: Bowman & Littlefield, 1998).