https://docs.google.com/open?id=1_6s9nASMWaUMM74ccWBPocFiwxDwbEyBIDKxTV7G-_yyW-mvy_i3wr_XDnci
this might be the same document
http://sdnorthzone.net/Communications/FleetMaps/North%20Zone%20VHF%20Mobile%20Fleetmap%20-%202010%20-Final%20V1.pdf