• [Wiki] https://en.wikipedia.org/wiki/Echinus_esculentus.
• [BIOTIC] http://www.marlin.ac.uk/biotic/browse.php?sp=4193.
• [EoL] http://eol.org/pages/599659/overview.
• [ComeAnse1988] Comely, C. A. and Ansell, A. D. (1988). Population density and growth of Echinus esculentus L. on the Scottish West Coast. Estuarine, Coastel and Shelf Science, 27:311--334.
• [Kooy2010] Kooijman, S. (2010). Dynamic Energy Budget theory for metabolic organisation. Cambridge Univ. Press, Cambridge.