1. Wallace, A. R. Mimicry and other protective resemblances among animals. Westminster Foreign Quart. Rev. 32, 1–43 (1867).
2. Wallace, A. R. The protective colours of animals. Science 2, 128–137 (1879).
3. Darwin, C. R. The descent of man, and selection in relation to sex (John Murray, London 1871).
4. Caro, T. Zebra stripes (Univ. Chicago Press, Chicago 2016).
5. Galton, F. South Africa (Minerva Library, New York 1851).