@article{HR10a,
  author   = {M.~Herrmann and J.~D.~M.~Rademacher},
  title    = {Riemann solvers and undercompressive 
              shocks of convex {FPU} chains},
  journal  = {Nonlinearity},
  volume   = {23},
  NUMBER   = {2},
  pages    = {277--304},
  year     = {2010}
}