@article{null,
  title={OPPERA-2 Conundrums and Challenges:  Lumping Versus Splitting? },
  author={rafael benoliel},
  journal={Journal of Oral & Facial Pain and Headache},
  volume={34},
  number={S1},
  pages={11--11},
  doi = {10.11607/ofph.2020.suppl.c4},
  year={2020}
}