  
  
  [1XReferences[101X
  
  [[20XWir98[120X]  [16XWirsching,  G.  J.[116X,  [17XThe  dynamical  system  generated  by the 3n+1
  function[117X,  Springer-Verlag,  Lecture  Notes  in  Mathematics,  [19X1681[119X,  Berlin
  (1998), viii+158 pages.
  
  
  
  [32X
