Name Info Provider Link
subscription/membership/fee required Atypon https://www.pnas.org/doi/10.1073/pnas.95.6.3157?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub 0pubmed
rrfF free resource BioCyc https://biocyc.org/gene?orgid=ECOLI&id=EG30091
free resource PubMed Central https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/9501232/
free resource Europe PubMed Central https://europepmc.org/abstract/MED/9501232