Rokoszewska, K.J. 2020. Intra-individual Variability in the Emergence of Lexical Complexity in Speaking English at Secondary School: A Case Study of a Good, Average, and Poor Language Learner. Theory and Practice of Second Language Acquisition. 6, 1 (Jun. 2020), 107–142. DOI:https://doi.org/10.31261/tapsla.7929.