3. John B. Cobb, Jr., Is It Too Late? A Theology of Ecology, rev. ed. (Denton, Tex.: Environmental Ethics Books, 1995), 112 pages.
4. Eugene C. Hargrove, Foundations of Environmental Ethics (reprint ed., Denton, Tex.: Environmental Ethics Books, 1996), 229 pages.
5. Robin Attfield, The Ethics of Environmental Concern (Denton, Tex.: Environmental Ethics Books, 1983), 237 pages.