@misc{Wikipedia-Stirling-Numbers-2015,
  author = "Wikipedia",
  title = "Stirling numbers of the second kind --- Wikipedia{,} The Free Encyclopedia",
  year = "2015",
  note = "\url{https://en.wikipedia.org/w/index.php?title=Stirling_numbers_of_the_second_kind&oldid=693800357}, [Online; accessed 12-December-2015]"
}

@book{Stanley-2012,
  author = "Richard P. Stanley",
  title = "Enumerative Combinatorics: Volume 1",
  publisher = "Cambridge University Press",
  year = "2012", 
  edition = "second"
}

@article{Discrete_Summation-AFP,
  author  = {Florian Haftmann},
  title   = {Discrete Summation},
  journal = {Archive of Formal Proofs},
  month   = apr,
  year    = 2014,
  note    = {\url{http://isa-afp.org/entries/Discrete_Summation.shtml},
            Formal proof development},
  ISSN    = {2150-914x},
}
