Couso, I., Garrido, L., & Sánchez, L. (2014). The notion of roughness of a fuzzy set. Fuzzy Sets and Systems, 249, 114-127. https://doi.org/10.1016/j.fss.2014.02.013
Sánchez, L., Couso, I., & Casillas, J. (2006). A Multiobjective Genetic Fuzzy System with Imprecise Probability Fitness for Vague Data. 131-136. https://doi.org/10.1109/ISEFS.2006.251156 (Original work published 2026)
