@MISC{FRIENDS1.MIZ,
  AUTHOR = {P\k{a}k, Karol},
  TITLE = {The Friendship Theorem},
  SECTION1 = {Preliminaries},
  SECTION2 = {The Friendship Graph},
  SECTION3 = {The Friendship Theorem},
  DAY = {15},
  MONTH = {May},
  YEAR = {2012},
  ADDRESS1 = {University of Bialystok, ul. Akademicka 2, 15-267 Bialystok},
  SUMMARY = {In this article we prove the friendship theorem
  according to the article \cite{MAlbert},
  which states that if a group of people has the property that any
  pair of persons have exactly one common friend,
  then there is a universal friend,
  i.e. a person who is a friend of every other person in the group.}}


@ARTICLE{MAlbert,
  AUTHOR =       {Michael Albert},
  TITLE =        {Notes On The Friendship Theorem},
  source = {http://www.math.auckland.ac.nz/~olympiad/Training/2006/friendship.pdf}
}
