Name	Info	Provider	Link
sulA	free resource	BioCyc	https://biocyc.org/gene?orgid=ECOLI&id=EG10984
	free resource	J-STAGE, Japan Science and Technology Information Aggregator, Electronic	https://joi.jlc.jst.go.jp/JST.Journalarchive/biochemistry1922/127.837?lang=en&from=PubMed
	subscription/membership/fee required	Silverchair Information Systems	https://academic.oup.com/jb/article-lookup/doi/10.1093/oxfordjournals.jbchem.a022677