The following formula is involved in the calculation of binomial probability values:

Binomial distribution probability mass function (PMF):
where x is the number of successes, n is the number of trials, and p is the probability of a successful outcome.

The following references can be used to cite this binomial probability calculator:
 Soper, D.S. (2015). Binomial Probability Calculator [Software]. Available from http://www.danielsoper.com/statcalc 
 Keller, G. (2011). Statistics for Management and Economics (9th edition). Mason, OH: SouthWestern Cengage. 