The study of QCD in the confinement regime poses some of the most difficult problems of fundamental physics at present. The mechanism of confinement itself is not described formally, and it is hard to investigate the properties of the fundamental theory in the determination of the structures and interactions of hadronic systems. The strong coupling and the extreme non-linearity of the theory severely limit the applicability and the extension and generalization of models and methods. The area of particle/nuclear physics called Hadron Physics deals with the phenomena determined by the...