Directorate of Telecommunications (DTELS) - Dedicated to former UK Home Office department responsible for providing wireless communication to Emergency Service and Central Government users from 1939 until it was privatised in 1994. - http://www.dtels.org
Motorola History - Motorola was founded by Paul V. Galvin as the Galvin Manufacturing Corporation, in Chicago, Illinois, in 1928. - http://www.motorola.com/content.jsp?globalObjectId=115-110
What is Two Way Radio? - History, information, and regulation. - http://www.ntia.doc.gov/openness/sp_rqmnts/mobile1.html
L.A.P.D. Communications - Unofficial history of the Los Angeles Police Department Communications Division detailed in a series of photographs. - http://www.snowcrest.net/marnells/kjc625.htm#links