D. Pauly, R. Watson, (2003). Scientific American 289, 42-47. 0036-8733, http://www.ecomarres.com/downloads/sad0703paul5p.pdf
D. Pauly, R. Watson, (2003). Scientific American 289, 42-47. 0036-8733, http://www.ecomarres.com/downloads/sad0703paul5p.pdf