@Article{1751-8121-41-22-224016,
  author = {Capocci, Andrea and Caldarelli, Guido},
  title  = {Folksonomies and clustering in the collaborative system CiteULike},
  journal = {Journal of Physics A: Mathematical and Theoretical},
  year   = {2008},
  number = {22},
  url    = {http://stacks.iop.org/1751-8121/41/224016},

  const  = {\ text}
}