@misc{indiciae690a215decea,
  title = {Adaptive evolution that requires multiple spontaneous mutations: mutations involving base substitutions.},
  author = {B G Hall},
  year = {1991},
  doi = {10.1073/pnas.88.13.5882},
  url = {https://pubmed.ncbi.nlm.nih.gov/2062865/},
  note = {Source identifier: 2062865}
}