@misc{Grahl2011,
  author    = {Martin Grahl},
  title     = {The O(N=2) model in polar coordinates at nonzero temperature},
  url       = {http://th.physik.uni-frankfurt.de/~giacosa/chiralgroup-Dateien/masterdiplom/Martin.pdf},
  institution = {Physik},
  type      = {diplom},
  year        = {2011},
}