• [Wiki] http://en.wikipedia.org/wiki/Gymnura_altavela.
• [fishbase] https://www.fishbase.se/summary/Gymnura-altavela.
• [AlkuAli2014] Alkusairy, H., Ali, M., Saad, A., Reynaud, C., and Capapé, C. (2014). Maturity, reproductive cycle, and fecundity of spiny butterfly ray, Gymnura altavela (Elasmobranchii: Rajiformes: Gymnuridae), from the coast of Syria (Eastern Mediterranean). Acta Ichthyologica et Piscatoria, 44(3):229--240. doi:10.3750/AIP2014.44.3.07.
• [Kooy2010] Kooijman, S. (2010). Dynamic Energy Budget theory for metabolic organisation. Cambridge Univ. Press, Cambridge.
• [ParsMais2008] Parsons, K. T., Maisano, J., Gregg, J., Cotton, C. F., and Latour, R. J. (2008). Age and growth assessment of western North Atlantic spiny butterfly ray Gymnura altavela (L. 1758) using computed tomography of vertebral centra. Environ Biol Fish, 74:736--742. doi:10.1007/s10641-017-0687-x.