• [Wiki] http://en.wikipedia.org/wiki/Raja_radula.
• [fishbase] http://www.fishbase.org/summary/Raja-radula.html.
• [KadrMaro2013] Kadri, H., Marouani, S., Bradai, M. N., and Bouaïn, A. (2013). Age, growth and reproductive biology of the rough skate, Raja radula (Chondrichthyes: Rajidae), off the Gulf of Gabes (southern Tunisia, central Mediterranean). Marine and Freshwater Research. doi:10.1071/MF12218.
• [Kooy2010] Kooijman, S. (2010). Dynamic Energy Budget theory for metabolic organisation. Cambridge Univ. Press, Cambridge.