query: SELECT T1.Airline FROM AIRLINES AS T1 JOIN FLIGHTS AS T2 ON T1.uid  =  T2.Airline WHERE T2.SourceAirport  =  "CVO" EXCEPT SELECT T1.Airline FROM AIRLINES AS T1 JOIN FLIGHTS AS T2 ON T1.uid  =  T2.Airline WHERE T2.SourceAirport  =  "APG"
question: It is departures from CVO but not from APG airports that which airlines have?
query_toks: SELECT T1.Airline FROM AIRLINES AS T1 JOIN FLIGHTS AS T2 ON T1.uid = T2.Airline WHERE T2.SourceAirport = `` CVO '' EXCEPT SELECT T1.Airline FROM AIRLINES AS T1 JOIN FLIGHTS AS T2 ON T1.uid = T2.Airline WHERE T2.SourceAirport = `` APG ''
query_toks_no_value: select t1 . airline from airlines as t1 join flights as t2 on t1 . uid = t2 . airline where t2 . sourceairport = value except select t1 . airline from airlines as t1 join flights as t2 on t1 . uid = t2 . airline where t2 . sourceairport = value
question_toks: It is departures from CVO but not from APG airports that which airlines have?