Allison Boughner
Comparison of biomarkers of exposure among US adult smokers, users of electronic nicotine delivery systems, dual users and nonusers, 2018–2019
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10163269/?fbclid=IwAR2ftvFV6mySHe3HmGPMsJK_N1IJp-IWltXYpcYN27cp3OyjLnbbgEoYyHE