Severity: Notice
Message: Undefined offset: 0
Filename: controllers/presentation.php
Line Number: 875
Severity: Notice
Message: Trying to get property of non-object
Filename: controllers/presentation.php
Line Number: 875
Author(s):
1. Igor Hut, Serbia
2. Katarina Čolić, Innovation Center of the Faculty of Mechanical Engineering, University of Belgrade, Serbia