Name Info Provider Link
subscription/membership/fee required Elsevier Science https://linkinghub.elsevier.com/retrieve/pii/S0306-4603(12)00098-6
Quitting Smoking free resource MedlinePlus Health Information https://medlineplus.gov/quittingsmoking.html
free resource PubMed Central https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22472523/
free resource Europe PubMed Central https://europepmc.org/abstract/MED/22472523