Sakalauskaitė, Greta, et al. “Comparison of Preoxygenation Efficiency With Intersurgical Economy and Intersurgical QuadraLite Anaesthetic Face Masks”. Acta Medica Lituanica, vol. 26, no. 1, May 2019, pp. 11-16, https://doi.org/10.6001/actamedica.v26i1.3950.