@misc{indiciaecf494a2c683f,
  title = {Bidirectional signals establish boundaries.},
  author = {R Klein},
  year = {1999},
  doi = {10.1016/s0960-9822(99)80441-2},
  url = {https://pubmed.ncbi.nlm.nih.gov/10508605/},
  note = {Source identifier: 10508605}
}