@misc{indiciae5ea7040bc7df,
  title = {A case study of student-directed discussion in four problem-based tutorial groups.},
  author = {L Wilkerson and J P Hafler and P Liu},
  year = {1991},
  doi = {10.1097/00001888-199109000-00048},
  url = {https://pubmed.ncbi.nlm.nih.gov/1930538/},
  note = {Source identifier: 1930538}
}