Surveillance methods and ways and means of communicating with drivers. Prepared for: National Academy of Sciences, Highway Research Board.

"Contract no. HR-63-3-2."

Air quality data from the national air surveillance networks and contributing State and local networks.

1967 ed. issued by Division of Air Quality and Emission Data, as APTD 69-22.

The effect of the ionosphere on communication, navigation, and surveillance systems : based on Ionospheric Effects Symposium, 5-7 May 1987 /

Mode of access: Internet.