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Several of the best-selling music artists in the world have competed in past editions , including ABBA , Celine Dion , Julio Iglesias and Olivia Newton-John , and some of the world 's best-selling singles have received their first international performance on the Eurovision stage .
 ABBA, Celine Dion, Julio Iglesias, Olivia Newton-John
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 ABBA, Celine Dion, Julio Iglesias, Olivia Newton-John