2. � � http://encarta.msn.com/find/Concise.asp?ti=0087B000

3. � � http://soma.npa.uiuc.edu/labs/nelson/electric_fish.html

4. � � http://saintbrendan.com/cdnmay/marinlf5.html

5. � � http://soma.npa.uiuc.edu/labs/nelson/electrolocation.html

6. � � http://www.bbb.caltech.edu/ElectricFish/brian/IwE/IwE.html

7. � � http://www.globalserve.net/~nberman/primer.html

8. � � http://www.howstuffworks.com/shark4.htm