Cláudia Silva and Fabio Silva. 1993.
 Finite Sets: A Case Study on Formal Program Development in the Extended ML Framework. In <em>Anais do VII Simpósio Brasileiro de Engenharia de Software</em>, outubro 27, 1993, Rio de Janeiro/RJ, Brasil. SBC, Porto Alegre, Brasil, 62-76. DOI: <a href="https://doi.org/10.5753/sbes.1993.24396">https://doi.org/10.5753/sbes.1993.24396</a>.