1 \chapter{Acknowledgements}
4 This page is dedicated to all those who were in any way involved with the outcome of this thesis.
6 First of all I want to express my utter gratitude towards my parents. They were there for me, constantly encouraging and supporting me generously in so many ways. Then there are my sisters Clara, Vroni and Anita, whose wonderful personalities make me a happier person. I want to thank my relatives and friends for being such an important part of my life and of who I am. Also, my colleagues are funny and inspiring people without exception and they have made my time as a student a pleasure.
8 Last but most certainly not least I am exceedingly grateful to my supervisors, Mag. Volker Christian and Dr. Walther Neuper.
10 Walther Neuper's enthusiasm for his project and his eager cooperation and supervision were extremely motivating and made the whole process of creating this thesis very efficient. His gentle and wise personality and his trust in me were very encouraging.
12 I owe my great appreciation to Volker Christian for his friendly personal and competent, professional supervision and his interest in my topic. I am overly thankful for his trust, support and encouragement to pursue my interests.
18 {\em For Franz, my uncle and godfather.}