Kroh, A.; Mooi, R. (2025). World Echinoidea Database.
Phormosoma rigidum A. Agassiz, 1881. Accessed through: Marine Species Traits editorial board (2025) Marine Species Traits at: https://www.marinespecies.org/traits/aphia.php?p=taxdetails&id=414210 on 2025-05-13
Marine Species Traits editorial board (2025). Marine Species Traits.
Phormosoma rigidum A. Agassiz, 1881. Accessed at: https://www.marinespecies.org/traits/aphia.php?p=taxdetails&id=414210 on 2025-05-13