| van Diggelen, F., Method and Apparatus for Time-Free Processing of GPS Signals, US Patent 6417801, Jul. 9, 2002. | | | | |
| http://www.navcen.uscg.gov/pubs/gps/icd200/ | | | | |
| http://www.glonass-ianc.rsa.ru/i/glonass/ICD-2002r.pdf | | | | |
| Mikhailov, N.V., Vasilyev, M.V., and Vasilyeva, N.V., Method of Autonomous Calculation of Long-Term Ephemeris in GNSS, XVI Sankt-Peterburgskaya mezhd. konf. po integrirovannym navigatsionnym sistemam (XVI St. Petersburg Int. Conf. on Integrated Navigation Systems), St. Petersburg: Elektropribor, May 2009. | | | | |
| Han, S., Navigation Positioning without Timing Information, US Patent 7535414, May 19, 2009. | | | | |