Few-Body Problems in Hadron Spectroscopy
  Some rigorous results can be derived using a very simple approach to hadron spectroscopy, in which a static potential is associated with non-relativistic kinematics. Several regularities of the experimental spectrum are explained by such models. It is underlined that certain methods developed for hadronic physics have found applications in other fields, in particular atomic physics. A few results can be extended to cases involving spin-dependent forces or relativistic kinematics. 
Jean-Marc Richard