Cita APA (7th ed.)

(1998). National Airspace System: FAA Has Implemented Some Free Flight Initiatives, but Challenges Remain.

Cita Chicago (17th ed.)

National Airspace System: FAA Has Implemented Some Free Flight Initiatives, but Challenges Remain. 1998.

Cita MLA (9th ed.)

National Airspace System: FAA Has Implemented Some Free Flight Initiatives, but Challenges Remain. 1998.

Atenció: Aquestes cites poden no estar 100% correctes.