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Leonardi Dutra, Kamile; Haas, Letícia; Porporatti, André Luís; Flores-Mir, Carlos; Nascimento Santos, Juliana; Mezzomo, Luis André; Corrêa, Márcio; De Luca Canto, Graziela . (2016). Diagnostic Accuracy of Cone-beam Computed Tomography and Conventional Radiography on Apical Periodontitis: A Systematic Review and Meta-analysis. Journal of Endodontics, 42(3), 356–364. doi:10.1016/j.joen.2015.12.015 
An interview with Sci-Hub Founder Alexandra Elbakyan,Who exactly should pay for academic research