Humphrey LL, Fu R, Buckley DI, Freeman M, Helfand M «Periodontal disease and coronary heart disease incidence: a systematic review and meta-analysis». J Gen Intern Med, 23, 12, 2008, pàg. 2079–86. DOI: 10.1007/s11606-008-0787-6. PMID: 18807098.
Humphrey LL, Fu R, Buckley DI, Freeman M, Helfand M «Periodontal disease and coronary heart disease incidence: a systematic review and meta-analysis». J Gen Intern Med, 23, 12, 2008, pàg. 2079–86. DOI: 10.1007/s11606-008-0787-6. PMID: 18807098.