Novo, Ernesto, et al. “A Possible Defective Estimation of Antineutrophil Cytoplasmic Antibodies in Systemic Lupus Erythematosus Due to the Coexistence of Periodontitis: Preliminary Observations”. Puerto Rico Health Sciences Journal, vol. 16, no. 4, Oct. 2019, https://prhsj.rcm.upr.edu/index.php/prhsj/article/view/1730.