1. University of Helsinki, Department of Economics and Management, P.O.Box 27, Latokartanokaari 9, FI-00014, Finland & University of Patras; Department of Business Administration of Food and Agricultural Enterprises; G. Seferi 2 Agrinio 30 100 Greece
2. University of Patras; Department of Business Administration of Food and Agricultural Enterprises; G. Seferi 2 Agrinio 30 100 Greece