1. Escola Superior de Comunicação Social, Lisbon, NECE-UBI - Covilhã, Portugal, Instituto Politécnico de Lisboa, Lisbon, Covilhã, Portugal
2. Faculty of Engineering, University of Porto, Porto, Portugal
3. DEGEIT, University of Aveiro, Aveiro, Portugal
4. School of Management, Hospitality and Tourism, Faculty of Economics, University of Algarve, Faro, Portugal