Preview citation in:
"binomial theorem". Oxford Dictionaries. Oxford University Press, n.d. Web. 31 October 2014.
<http://www.oxforddictionaries.com/definition/english/binomial-theorem>.

"binomial theorem". Oxford Dictionaries. Oxford University Press.
http://www.oxforddictionaries.com/definition/english/binomial-theorem (accessed October 31, 2014).