[1] Polytech Leiria, Sch Technol & Management, Dept Math, Leiria, Portugal
[2] Coimbra Business Sch, ISCAC Higher Inst Accounting & Adm, Coimbra, Portugal
[3] La Trobe Univ, La Trobe Business Sch, Dept Management Sport & Tourism, Melbourne, Vic, Australia
[4] ISCET Higher Inst Business & Tourism, Coimbra, Portugal
[5] Univ Aveiro, Dept Ind Management, Aveiro, Portugal
[6] Univ Vigo, Vigo, Portugal
[7] ISCET Inst Super Ciencias Empresariais & Turismo, Porto, Portugal
[8] Univ Porto, Porto, Portugal
[9] Univ Porto, FCUP Fac Ciencias, Porto, Portugal