@article{2204,
  author = {A. Lytle and X. Zhang and P. Arpin and O. Cohen and Margaret Murnane and Henry Kapteyn},
  title = {Quasi-phase matching of high-order harmonic generation at high photon energies using counterpropagating pulses},
  year = {2008},
  journal = {Optics Letters},
  volume = {33},
  pages = {174},
  month = {2008-01},
  doi = {10.1364/OL.33.000174},
}