00313nam a2200097Ia 4500080002100000245010200021260002900123300002700152583001800179650001800197  a10.05.01 C2771ch  aChanges to the air traffic services requirements for air-ground and point-to-point communications  bICAOa[Montreal]CAc1999  a1 v. (various pagings)  c7/10/07kJOYD  aAIR TRANSPORT