THACKERAY, J. F.; SCHREIN, C. M. A probabilistic definition of a species, fuzzy boundaries and ‘sigma taxonomy’. South African Journal of Science, [S. l.], v. 113, n. 5/6, p. 2, 2017. DOI: 10.17159/sajs.2017/a0206. Disponível em: https://sajs.co.za/article/view/3794. Acesso em: 2 jul. 2022.