• [Wiki] http://en.wikipedia.org/wiki/Urechis_unicinctus.
• [Goul1969] Gould, M. C. (1969). A comparison of RNA and protein synthesis in fertilized and unfertilized eggs of Urechis caupo. Developmental Biology, 19:482--497.
• [Kooy2010] Kooijman, S. (2010). Dynamic Energy Budget theory for metabolic organisation. Cambridge Univ. Press, Cambridge.
• [Suer1984] Suer, A. L. (1984). Growth and spawning of Urechis caupo (Echiura) in Bodega Harbor, California. Marine Biology, 78:275--284.