Laursen, K., Essink, K., Essink, K. (red.), Dettmann, C. (red.), Farke, H. (red.), Laursen, K. (red.), Lüerssen, G. (red.), Marencic, H. (red.) & Wiersinga, W. (red.) (2005).
Offshore Area. I
Wadden Sea Ecosystem (s. 265-271). Wilhelmhaven: Common Wadden Sea Secretariat (CWSS).
http://www.waddensea-secretariat.org/QSR/index.html