The impact of digital influencers on product/service purchase decision making - An exploratory case study of Portuguese people. - Fábio Caiado; Joana Fonseca; Joana Silva; Soraia Neves; Ana Moreira; Ramiro Gonçalves; José Martins; Frederico Branco; Manuel Au-Yong-Oliveira (Expert Syst. J. Knowl. Eng., 2025)