Name Info Provider Link
subscription/membership/fee required Elsevier Science https://linkinghub.elsevier.com/retrieve/pii/0091-3057(87)90619-8
Caffeine free resource MedlinePlus Health Information https://medlineplus.gov/caffeine.html
free resource NCI CPTAC Assay Portal https://assays.cancer.gov/CPTAC-511