D. Höchtl, U. Schmid:
"Long-Term Evaluation of GPS Timing Receiver Failures";
Talk: IEEE PTTI Systems and Application Meeting, Long Beach, CA, USA; 1997; in: "Proc. of the 29th IEEE PTTI Systems and Application Meeting (PTTI'97)", (1997), 165 - 180.
http://www.auto.tuwien.ac.at/Projects/SynUTC/papers.html