@conference{805616,
  author = {D Davis and Marc Weiss and K Davies and Gerard Petit},
  title = {Improving GPS Time Transfer Accuracy with the NIST Ionospheric Measurement System},
  year = {1991},
  month = {1991-01-01 00:01:00},
  publisher = {4^uth^ Annual Ion GPS Intl. Tech. Meeting , Albuquerque, NM, USA},
  language = {en},
}