@article{etna_vol40_pp36-57,
  author  = {Xiuhong Du and Marcus Sarkis and Christian E. Schaerer and Daniel B. Szyld},
  title   = {Inexact and truncated Parareal-in-time Krylov subspace methods for parabolic optimal control problems},
  journal = {Electron. Trans. Numer. Anal.},
  volume  = {40},
  year    = {2013},
  pages   = {36--57},
}