SHEAR, W. A. Cave millipeds of the United States. XI. Opiona graeningi, n. sp., a troglomorphic caseyid milliped from Siskiyou County, California, with comments on the genus Opiona Chamberlin 1951 (Diplopoda, Chordeumatida, Caseyidae). Zootaxa, Auckland, New Zealand, v. 3114, n. 1, p. 50–56, 2011. DOI: 10.11646/zootaxa.3114.1.5. Disponível em: https://www.mapress.com/zt/article/view/zootaxa.3114.1.5. Acesso em: 3 may. 2025.