IberLEF 2021 task overviews have been published in the Journal Procesamiento del Lenguaje Natural, vol 67, september 2021 (open access).
System descriptions, together with a detailed report of IberLEF 2021 activities, appear in IberLEF 2021: Iberian Languages Evaluation Forum, CEUR Workshop Proceedings vol. 2943, ISSN 1613-0073.