00342nam a2200109Ia 450000500170000008000210001724501020003826000290014030000270016958300180019665000180021420260716043823.0  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