@article{18956,
  author = {Macedo L. and Herbert Rob and McAuley J. and Kamper S. and Maher C.},
  title = {Imperfect placebos are common in low back pain trials. A systematic review of the literature},
  year = {2008},
  journal = {European Spine Journal},
  volume = {17 },
  number = {7},
  pages = {889-904.  },
  language = {eng},
}