First Author:   Denis Stijepic University of Hagen denis.stijepic@fernuni-hagen.de   Fernuniversitaet in Hagen, Fachbereich Wirtschaftswissenschaften, Universitaetsstr. 41 Hagen, D-58084, Germany   +49(0)2331/987-2640(Phone) +49(0)2331/987-2640(Fax) http://www.fernuni-hagen.de/ls_wagner/team/denis.stijepic.shtml