@article{CTT100572330,
  author = {K. Ozawa and Y. Oba and K. Edamoto and M. Higashiguchi and Y. Miura and K. Tanaka and K. Shimada and H. Namatame and M. Taniguchi},
  title = {Valence-band structure of the polar ZnO surfaces studied by angle-resolved photoelectron spectroscopy},
  journal = {Physical Review B},
  year = 2009,
}