@article{syljuasen2002,
  author = {Syljuåsen, O. F. and Sandvik, A. W.},
  title = {{Quantum Monte Carlo with Directed Loops}},
  journal = {Physical Review E},
  volume = {66},
  number = {4},
  pages = {046701},
  year = {2002},
  doi = {10.1103/PhysRevE.66.046701}
}