Luba, O.; Boyd, L.; Gower, A.; Crum, J. (April 2004). "GPS III system operations concepts". PLANS 2004. Position Location and Navigation Symposium (IEEE Cat. No.04CH37556). pp. 380–388. doi:10.1109/PLANS.2004.1309020. ISBN0-7803-8416-4. S2CID21180313.
"Archived copy"(PDF). www.lockheedmartin.com. Archived from the original(PDF) on 2014-07-05. Retrieved 2015-05-17.{{cite web}}: CS1 maint: archived copy as title (link)
Luba, O.; Boyd, L.; Gower, A.; Crum, J. (April 2004). "GPS III system operations concepts". PLANS 2004. Position Location and Navigation Symposium (IEEE Cat. No.04CH37556). pp. 380–388. doi:10.1109/PLANS.2004.1309020. ISBN0-7803-8416-4. S2CID21180313.
"Archived copy"(PDF). www.lockheedmartin.com. Archived from the original(PDF) on 2014-07-05. Retrieved 2015-05-17.{{cite web}}: CS1 maint: archived copy as title (link)