Bilden og tildels teksten er hentet fra A guide to the shell and starfish galleries. Department of zoology, British Museum (Natural History). 1901., sider 88–89; sannsynligvis forfattet av Sir Edward Ray Lankester. Bilden er opprinnelig fra Lankesters bok Degeneration. A chapter in darwinism (1880).
doi.org
Fedonkin, M. A.; Vickers-Rich, P.; Swalla, B. J.; Trusler, P.; Hall, M. (2012). «A new metazoan from the Vendian of the White Sea, Russia, with possible affinities to the ascidians». Paleontological Journal. 46: 1–11. doi:10.1134/S0031030112010042.
Ogura, Y; Sasakura, Y (2013). «Ascidians as excellent models for studying cellular events in the chordate body plan». Biol Bull. 224 (3): 227–36. PMID23995746. doi:10.1086/BBLv224n3p227.
marinespecies.org
Gittenberger, A.; Shenkar, N.; Sanamyan, K. (2015). "Ascidiacea". In: Shenkar, N.; Gittenberger, A.; Lambert, G.; Rius, M.; Moreira Da Rocha, R.; Swalla, B. J.; Turon, X. (2017). Ascidiacea World Database. Accessed through: World Register of Marine Species on 2017-09-15.
Ogura, Y; Sasakura, Y (2013). «Ascidians as excellent models for studying cellular events in the chordate body plan». Biol Bull. 224 (3): 227–36. PMID23995746. doi:10.1086/BBLv224n3p227.
