T. Viana, J. Duarte, M. Pessoa, and F. Pires.
" Mathematical Forest: a proposal to exercise mental calculation", in <em>Companion Proceedings of the 13th Brazilian Congress on Computers in Education</em>, Rio de Janeiro/RJ, 2024, pp. 225-228, doi: <a href="https://doi.org/10.5753/cbie_estendido.2024.244464">https://doi.org/10.5753/cbie_estendido.2024.244464</a>.