Reich & Haude 2004 Reich, M.; Haude, R. (2004). "Ophiocistioidea (fossil Echinodermata): an overview". Echinoderms: München. London: Taylor & Francis. pp. 489–494. doi:10.1201/9780203970881.ch82 (inactive 2024-11-12).{{cite book}}: CS1 maint: DOI inactive as of November 2024 (link)
Smith & Reich 2013, pp. 677–678 Smith, Andrew B.; Reich, Mike (2013). "Tracing the evolution of the holothurian body plan through stem-group fossils". Biological Journal of the Linnean Society. 109 (3): 670–681. doi:10.1111/bij.12073.