1. Allan D, Hellwig H, Kartaschoff P, Vanier J, Vig J, Winkler G, Yannoni N (1988) Standard Terminology for Fundamental Frequency and Time Metrology, Proc. 42nd Annu. Freq. Control Symp., pp.419-425 1988 :IEEE Press
2. Bonnedal M, Christensen J, Carlström A, Lindgren T, Marquardt C, von Engeln A, Andres Y, Larsen G, Lauritsen K, Syndergaard S, Benzon H, Sørensen M, Gorbunov M, Kirchengast G, Pirscher B, Schweitzer S, Fritzer J, Montenbruck O, Zus F, Beyerle G (2012) GRAS Radio Occultation Performance Study, Issue 3 Draft, RUAG Space AB, Göteborg, Sweden, pp.73-4,182-3,P-GRDS-REP-00002-RSE
3. Borre K, Akos D, Bertelsen N, Rinder P, Jensen S (2007) A Software-Defined GPS and Galileo Receiver: A Single-frequency Approach. Birkhäuser, Boston
4. Cardinali, C (2009) Forecast sensitivity to observation (FSO) as a diagnostic tool, ECMWF Technical Memorandum., pp 599:626
5. Daly P, Kitching I (1990) Characterization of NAVSTAR GPS and GLONASS On-Board Clocks. IEEE AES Mag., July, pp. 3–9, 0885/8985/90/0700/0003