Stopar, Andrej y Gašper Ilc. «Item and task difficulty in a B2 reading examination: perceptions of test-takers and CEFR alignment experts compared with psychometric measurements». Círculo de Lingüística Aplicada a la Comunicación, vol. 67, vol. 67, 2016, pp. 318-42, doi: https://doi.org/10.5209/CLAC.53487.