1. “Application of Area Navigation in the National Airspace System A report by: FAA/Industry RNAV Task Force February 1973
2. Harris , R. M. et al An Advanced Air Traffic Management Concept Based on Extensions of the Upgraded Third Generation ATC System MTR-6419 March 1974
3. Scott , R. E. Study and Evaluation of the Omega Navigation System for Transoceanic Navigation by Civil Aviation The University of Michigan, FAA Report RD-69-39 August 1969