Sypiańska, J., and Z. Cal. “The Influence of Level of Proficiency in the L2 and L3 on the Production of the L3 Spanish Apico-Alveolar Sibilant”. Research in Language, vol. 18, no. 1, Mar. 2020, pp. 89-107, doi:10.18778/1731-7533.18.1.06.