- Society for Animal Protective Legislation47
- Stevens, Christine28
- Regan, Tom24
- Animal Welfare Institute21
- United States. Congress10
- United States. Department of Agriculture10
- Cohen, Carl, 1931-9
- Singer, Peter, 1946-9
- American Society for the Prevention of Cruelty to Animals5
- Mattox, John5
- North Carolina State University. Department of Communication5
- Rawls, John, 1921-20024
- Darwin, Charles, 1809-18823
- Gandhi, Mahatma, 1869-19483
- National Anti-Vivisection Society3
- Animal Defence and Anti-Vivisection Society2
- Aristotle2
- Descartes, Rene, 1596-16502
- Frey, R. G. (Raymond Gillespie)2
- Mills, Ralph2