N. Báez Ureña, E. Rincón Santana, R. Blanco Sánchez, and M. Angeris Artiles, “The movement of the variable in one-sided limits as resource for teaching differential calculus”, Trans, vol. 22, Sep. 2026, Accessed: Sep. 28, 2026. Available: https://transformacion.reduc.edu.cu/index.php/transformacion/article/view/670