Campbell, S., R. 2004. Embodied Minds and Dancing Brains: New Opportunities for Research in Mathematics Education. Canada: Faculty of Education, Simon Fraser University. (Online), (https://books.google.com/books=campbell+2004+thinking&source=bl&ots=WTaCFcUWuH&sig=Utf83a8AbiIC3tPpzT3Y6M77kZo&hl=id&sa=X&ei=r66nVNf0EMz5auegfgO&ved=0CFkQ6AEwCzgK#v=onepage&q=campbell%202004%20thinking&f=false), diakses 14 juli 2013.