Limits of Localizer Coverage
U.S. Dept. of Transportation, Federal Aviation Administration,
Aeronautical Information Manual, <a rel="nofollow" class="external free" href="https://www.faa.gov/air_traffic/publications/media/AIM_Basic_dtd_10-12-17.pdf">https://www.faa.gov/air_traffic/publications/media/AIM_Basic_dtd_10-12-17.pdf</a>