Author(s):
1. Silvana Angelevska, Faculty of Technical Sciences in Bitola, University St. Climent Ohridski, Macedonia
2. Ivo Kuzmanov, Univerzitet Metropolitan, Macedonia
3. Zore Angelevski, Faculty of Technical Sciences in Bitola, University St. Climent Ohridski, Macedonia
4. Vasko Stojanovski, Faculty of Technical Sciences in Bitola, University St. Climent Ohridski, Macedonia