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The Regia Aeronautica ( Italian Royal Air Force ) declined purchase of the final six production aircraft , which Ala Littoria then also bought .
 Regia Aeronautica, Ala Littoria
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Regia Aeronautica, Ala Littoria