Source: https://www.researchgate.net/profile/Mourad-Touzani/publication/260986872_Le_processus_de_validation_des_echelles_de_mesure_fiabilite_et_validite/links/0c960532eaee81c7c0000000/Le-processus-de-validation-des-echelles-de-mesure-fiabilite-et-validite.pdf