World Register of Marine Species (WoRMS)
Protokionoceras loricatum (Barrande, 1868)
MolluscaBase eds. (2026). MolluscaBase. Protokionoceras loricatum (Barrande, 1868)&nbsp;&#8224;. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1872368 on 2026-08-30
Barrande, J. (1865–1877). Systême silurien du Centre de la Bohéme, I. ère partie: Recherches Paléontologiques, vol. II, Classe de Mollusques, Ordre des Céphalopodes. Prague and Paris, privately published in instalments: 1865, ser. 6, pls 1–107; 1866, ser. 7, pls 108–244; 1867, ser. 1, 712 p.; 1868, ser. 8, pl. 245–350; 1870, ser. 2, 266 p., ser. 9, pl. 351–460; 1874, ser. 3, 804 p.; 1877, ser. 4, 742 p., ser. 5, 743 p.; Supplement 1, 297 p.; Supplement 2, pl. 461–544.