TY  - RPRT
TI  - Adaptive evolution that requires multiple spontaneous mutations: mutations involving base substitutions.
AU  - B G Hall
PY  - 1991
DO  - 10.1073/pnas.88.13.5882
UR  - https://pubmed.ncbi.nlm.nih.gov/2062865/
ID  - 2062865
ER  -