' http://listverse.com/2013/01/26/10-pairs-of-commonly-confused-animals/' http://artikel.okeschool.com/artikel/hewan/399/perbedaan-buaya-dan-alligator.html' http://belajar-sampai-mati.blogspot.com/2011/02/apa-perbedaan-lumba-lumba-dengan-pesut.html?m=1'
