@conference{121646,
  author = {A Uljanov and Vladislav Demidov and E Mattison and R Vessot and D Allan and G Winkler},
  title = {Performance of Soviet and U.S. Hydrogen Masers},
  year = {1991},
  month = {1991-01-01},
  publisher = {22^und^ Annual Precise Time and Time Interval Meeting , Tysons Corner, VA},
  language = {en},
}