ten Bruggenkate CM, Lopes Cardozo E, Maaskant P, van der Waal I. (1975), "Lead poisoning with pigmentation of the oral mucosa. Review of the literature and report of a case" ; Oral Surg Oral Med Oral Pathol. 1975 May;39(5):747-53. (https://www.ncbi.nlm.nih.gov/pubmed/806864 résumé])