Salamanca - Garay I, Sagredo - Lillo E. Design and Validation of a Perception Instrument for Educational Communities on the Stimulation of 21st- Century Skills in Students within the School System. epsir [Internet]. 2024 Sep. 19 [cited 2026 Nov. 5];10:1-16. Available from: https://epsir.net/index.php/epsir/article/view/883