World Register of Marine Species (WoRMS)
Stöhr, S.; O’Hara, T.; Thuy, B. (Eds) (2026). World Ophiuroidea Database. Amphiophiura hadra (H.L. Clark, 1911). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=242704 on 2026-08-29
Clark, H. L. (1911). North Pacific Ophiurans in the collection of the United States National Museum. Smithsonian Institution United States National Museum Bulletin. 75: 1-302.