@misc{indiciae83e373a06b56,
  title = {Challenging artificial genetic systems: thymidine analogs with 5-position sulfur functionality.},
  author = {Heike A Held and Steven A Benner},
  year = {2002},
  doi = {10.1093/nar/gkf500},
  url = {https://pubmed.ncbi.nlm.nih.gov/12202771/},
  note = {Source identifier: 12202771}
}