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[ 2 ] J.F. Bard ( 1984 ) , “ An investigation of the linear tree level programming problem ” IEEE Transactions on Systems , Man and Cybernetics , 14:711 -717 .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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