Fedonkin et al. 2012 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. S2CID128415270.
Jeffries Jeffries, R. P. S. "Two types of bilateral symmetry in the Metazoa: chordate and bilaterian". Dalam Bock, Gregory R.; Marsh, Joan (penyunting). Biological Asymmetry and Handedness. Ciba Foundation Symposium. John Wiley and Sons. doi:10.1002/9780470514160.ch7.
Fedonkin et al. 2012 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. S2CID128415270.