Lewis, P., Lewis, P., Fradley, S., Griffiths, A., Baxter, P., & Parry, J. (2002). Mitochondrial DNA mutations in the parotid gland of cigarette smokers and non-smokers. Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 518(1), pp. 47-54. doi:10.1016/S1383-5718(02)00066-9

Lewis, Paul, P.D Lewis, S.R Fradley, A.P Griffiths, P.W Baxter, and J.M Parry. "Mitochondrial DNA Mutations in the Parotid Gland of Cigarette Smokers and Non-smokers." Mutation Research/Genetic Toxicology and Environmental Mutagenesis 518, no. 1 (2002): 47-54.

Lewis, Paul, et al. "Mitochondrial DNA Mutations in the Parotid Gland of Cigarette Smokers and Non-smokers." Mutation Research/Genetic Toxicology and Environmental Mutagenesis 518.1 (2002): 47-54.